We've just gone through the same exercise - looking at all the car seats on the market ad trying to make a decision on which one is the best for our first bub.

Our first pick was the Safe N Sound Meridian AHR Tilt & Adjust (the new one on the market) but we ended up deciding against this one as we spoke to several people who said while it is the rolls royce of car seats it is very large and depending on your current car size and potential for future bubs it can be a real limitation.
The people we spoke to drove a Mazda 3, Toyota Corolla and Lancer - all sort of mid range cars.

We were adamant on the Safe N Sound brand, so we purchased the Safe N Sound Compaq Deluxe. It apparently has all the same safety features as other Safe N Sound car seats, however the sides are not as flanged so should we ever need to we can fit three of these car seats across the back seat of our car.

We have since had the car seat fitted (only 4 weeks to go till Miss Martini arrives!) and it fits really well into our car, plenty of room for the front passenger and driver to move their seats back and be in a comfortable position to drive.