I remember when the very first swivel seat came out (Maxi Cosi Axiss) in about 2010 I want to say, and MN was absolutely raving about it. Genius invention, everyone said.
Nowadays there is a huge amount of choice and most of them also rear face which is great. I agree it's a good idea to wait until your baby is close to outgrowing their baby seat. The baby seats are convenient to have for the first year or so, tend to fit all babies reasonably well and then you'll actually have the baby, so you can go to a shop and try different seats out. Look for a local independent retailer if you can, they tend to give better advice than chains. Not always, it's a generalisation.
Swivel is a nice feature, but it's also worth looking at safety rating - it is a potentially lifesaving device after all, and rotation is quite a complicated thing to add into a device that is designed to handle massive forces. I'd probably only use a swivel seat model that has a good safety rating, or from a brand that has a long standing history of good safety ratings. (Check Which, or you can read the test results in German on ADAC for free if you don't want to buy a Which subscription) If in doubt, stick to something simple.
Also important: ease of use, how it fits your car and crucially how it fits your child and is likely to fit them as they grow. A few people have mentioned that swivel type seats max out at 105cm height or 18kg weight - this is based on an average 4 year old, but about 40% of children will reach one or the other of those milestones before the age of 4 - and you only need to hit one for the seat to be outgrown. If your child is even slightly taller or heavier than average, it may be worth investing in a seat with higher limits such as 25kg or 125cm, if you don't think you'll have another baby to hand the toddler seat down to.
Car fitting issues can include the angle if you have angled seats/isofix points, plus the amount of space for the front seat passenger or driver.
Extended rear facing capability is definitely worth considering as it's safer. With the newer i-size seats, children must rear face to a minimum of 15 months but longer is better 