I'm impressed with it so far, though haven't actually road tested yet, mainly because I only have one baby to go in it as yet.
The chassis is quite long, (and a bit of a juggernaut frankly, if you place the carry cot at the front), but it means both children have plenty of leg room, which is what put me off most tandems, including the Jane Powertwin. When the seats are reclined, the child at the back seems to have the front seat on its legs. I decided against a side by side, as I wouldn't get through any of my local shop doors with one.
The Zoom chassis seems well constructed. It's very easy to fold, though you do have to take the seats off first. I decided this was actually a good thing, as the chassis folds to the same size as say, a Bugaboo frame and then if you're short on boot space for shopping and so on, you can put the buggy seats behind the front seats of the car. (No iCandy "pip" converter frame making the process more complicated than it needs to be.)
The seats seem a little light and plastic-y, and the fabric a bit lighter weight than I would like, but I think that's partly because my last buggy was a Mountain Buggy, so particularly sturdy.
Another advantage I saw in the Zoom, is that the heaviest child can go at the back, whereas even with the iCandy Pear, the biggest seat is at the front so it's harder to get up kerbs. The Zoom manoeuvres well despite it's length and doesn't seem too heavy to me, even at 36 weeks pregnant.
Seats are well padded and comfy and the bumper bars can be unclipped on either side to make it easier to insert child to seat. The seats are also nice and big, bigger than the iCandy imo, though I haven't measured. Certainly in the iCandy Pear, DD2's head was touching the hood when she sat in it and I was told I'd need to buy an Apple hood, which is bigger. It comes with detachable hoods as standard. The seats lie very flat. They say they're suitable from 6 months, but tbh, when DD1 was a baby (13 years ago), that's the kind of seat she had - where the baby's back is flat, but their legs stick up a bit, iyswim. Flatter than a car seat for sure. The carry cot is MASSIVE and will definitely last 6 months. I think it's bigger than a Mountain Buggy carry cot and definitely bigger than the iCandy carry cot.
Shopping basket is a great size (due to length of chassis I suppose!). Nice fat rubber tyres - not pneumatic, so no punctures.
The only thing is the raincover. It's crap. It's just a big cheapo bit of plastic, which doesn't appear to even clip on anywhere, it just fits over both seats (or seat and carrycot). I'm going to look into getting either two universal raincovers so each seat can be covered separately, or bring the pushchair to a pram shop to see if the covers for another tandem cover would fit over. Either that or I will attach some Velcro straps to the one they've provided.
You can't use as a "proper" single buggy as with an iCandy Pear or Phil and Teds, (well, you can take one seat off, but you still have the long chassis anyway), but I have such a small age gap (14 months) that I reckon they'll both be buggy-ing for long enough to make this worthwhile and I have a Mamas and Papas Nipi (which is suitable from birth) for any trips out with a single child. I'm sure I'll be glad of the rest from the double if I just take one child out!
What else? Handlebar is height adjustable in the same manner as a Bugaboo. You can buy adaptors (about £12 I think) for the Maxi Cosi cabrio - I'm just waiting for those to be delivered. They also sell a car seat especially for this buggy. If you have an older child, they also sell a buggy board designed for this pushchair.
The thing I like best of all is that the seats, carry cot and car seat can all go on either slot in either direction, so you can have both children facing you, or facing each other if you like. I thought that was lovely and it seems rare in a tandem.
My main reason for buying this was that I wanted a pushchair in which I knew the children would be lovely and comfortable, rather than buying the lightest/ smallest/ most convenient pushchair for me. This ticks all the boxes for what I need it to do.
Hope that helps. When DD2 wakes up, I'll take some pics of her in it, which should give a better idea of the size of it, rather than the manufacturers pictures.