Hi Trav123 :)
Is your criteria that the seat can be used with the iCandy and have access to an isofix base (possibly a base which can take a toddler seat?) - If so, you have a much wider selection of seats you can look at, if you'd like more info?
Out of the three you've suggested:
The Joie i-gemm is a really long lasting infant seat and great value for money. Joie don't overprice their seats, and I really appreciate that. The isofix base as well is reasonably priced which is important to factor into the decision, as sometimes they can be more expensive than the seat! The downside of this seat is that it's not that padded/supportive/lie-flat for newborns - which is a relatively short term issue, and only one which has come up in recent years as certain seats on the market have prioritised this as a selling point. If you're likely to stay close to home in the first 6-8 weeks, I wouldn't worry about this at all, as long term this seat has more positives which balance out this part.
The maxi cosi Pebble pro and plus are fairly similar to each other. I think I like the head cushion a bit better on the Pro. These seats are much flatter and more cradle-like for a young baby and I think that's a plus, but the big downside, other than price, is that both of them have a small height/length limit of 75cm, which means that a larger than average child is likely to outgrow it by about 6-9 months of age, an average child 10-11 months. That can be a problem if the seat you have for the next stage is fairly upright (as the maxi cosi ones in particular tend to be) and some people find this a problem for sleeping in the car as the child's head tends to flop forwards, which looks uncomfortable. Additionally, if you choose a forward facing seat for the next stage, your baby is unlikely to reach the required 15 months before going into it, so you'll definitely need a rear facing seat or you'll need to buy another seat for the interim. By comparison, the Joie with the height/length limit of 85cm will easily last an average child over 18 months and even a larger-than-average child will get over a year in the seat. Not necessarily a problem, depending on which seat you get for the next stage, but worth being aware of.
In terms of crash testing all three are excellent. They all perform slightly better off the base than on it. Out of the pro and the plus, the plus is slightly better. I don't have numerical data to compare for Joie, but it looks comparable - I'd say all three are about the same with negligible differences in safety.
Here's a comparison (in German, but if you open in Google Chrome and wait for a moment, it should ask if you want it to translate.)
www.adac.de/infotestrat/tests/kindersicherung/kindersitz-test/vergleich.aspx?id1=385&id2=596&id3=408&nc=True&ergo=True
The future
Separated, because it's long and might be too much to think about right now, in which case, base your decision on the baby seat and think about this part later. But in that case, don't factor in a modular base to your decision - just pick the best seat/base combo for now.
Modular bases, where you can fit both an infant seat and toddler seat onto the same base, are a very popular idea in car seats at the moment, and I think it all looks very sensible from where you're standing. The problem is that when you get to about 6-12 months down the line and you're eyeing up next stage seats, it all becomes complicated again.
Firstly: Be aware the manufacturer of the seat has ££ signs in front of their eyes; they are imagining you getting to this stage and going "OK, let's choose from the seats which fit on this base" = guaranteed sale for that company. Which might be the right seat for you, but also, why limit yourself to a tiny selection of 1-4 seats (depending on brand)? Unless you're willing to do the research now and base your infant seat decision on this, it is very limiting.
Secondly: If you widen your search to all seats suitable for after this stage, you'll find that a great many of them don't require a separate base at all. So the idea that you will save money by already having a base is flawed, and in addition, many of these seats which go onto the (very expensive) base cost about as much (on top of the base you've already purchased) as a seat which doesn't need a base at all!
Thirdly: If you have another baby before your first is about 4 years old, you will most likely want that base back for the infant seat, but it will be in use for the older child. So you will have to decide whether to use the new baby's seat without a base or change the older child's seat or buy a second base (for each car). Obviously, doesn't apply if you're only having one child.
But the main point is: By limiting yourself to modular-base-compatible toddler seats, you're discounting swivel/spin seats (unless you go with Cybex from the start), which many parents find an extremely attractive/convenient prospect - and from all brands, limiting yourself to only seats which are suitable up to a maximum of 18kg/105cm. Seats for the toddler stage come in two sizes - up to 18kg/105cm, which will last until your child outgrows age 3-4 in clothing, or up to 25kg/125cm, which last roughly until children outgrow age 6-7 clothing. If you have a child who is large for their age, they are likely to outgrow an 18kg seat by about 3, sometimes younger, depending on the size and shape of the seat. Most people would find that too young to go into a booster seat, meaning that you end up having to fork out again for a seat up to 25kg. Since the up to 25kg seats can also be used immediately after the baby seat, it makes sense to just get one of these in the first place, and none of them are modular (fit onto infant seat bases).
Phew - OK - one last point, which you didn't really ask but I'll be cheeky and point it out anyway: Rear facing vs forward facing after the baby stage. Obviously all infant seats are rear facing only, which is because it's much safer. Forward facing car seats reduce injuries to children in collisions (compared with being unrestrained/using a too-big seatbelt) by 60%, which is fantastic and why it's law to use a car seat. But a rear facing seat at any age will reduce injuries by over 90%. So you really want to maximise rear facing time as much as you can, especially for younger children as they are more vulnerable and car accident injuries can be life changing or even life ending. In addition, if you buy an i-size seat (like the three you mention), it's the law to keep your baby rear facing until a bare minimum of 15 months old. But longer is better. You have a few options about how to do this:
Option 1: Use the baby seat as long as possible - everyone can do this, you have it anyway, it's a totally cost-zero option. Downside is these seats are really optimised for ages 0-6 months, toddlers tend to dislike them as they have no view and are forced to lie down. But if you don't have your own car or need to save money, it's definitely doable. When it gets too heavy to carry, you can just leave it permanently in the car.
Option 2: Buy a toddler seat that can rear face up to 13kg/87cm, and then forward face to 18 or 25kg (e.g. Maxi Cosi Asissfix Plus, Maxi Cosi Beryl, Britax First Class Plus) - does not get you much longer than the infant seat, but you'll get a little longer in terms of height and the seat being more upright, which curious toddlers often prefer.
Option 3: Buy a toddler seat which can rear face to 18kg - loads of these on the market now, including some compatible with the bases you're looking at. Will give you the option to RF until 3-4 years, depending on size of child. Many can also face forward allowing you to delay the decision. These days there is very little point in going for option 2, as option 3 is affordable and widely available, unless you have a particular situation e.g. difficult storage boxes in car, living abroad with poor selection of seats.
Option 4: Buy a toddler seat which can rear face until 25kg - absolutely maximises rear facing time, there are more of these seats available in the UK now and the cost is roughly comparable with the mid-to-top range of option 3. However they are often only available from specialists (which is no bad thing, as they offer an excellent service) and they are only really suitable from about 12 months+ as they are more upright than other seats.
