C.K.
Hi
We used the snugride with great success. we used it until our son was about 10 months old. i have a friend who loves the britax seats for her bigger kids (she's also a car seat inspector) but used the snugride when they were infants. the problem with the bigger convertible seats is that if your baby is born on the small side they may not sit comfortably (or safely!) in the convertible seat. i know that they are ok for use at 5 lbs but some babies just don't like the ride.
the snugride for us was awesome, super easy installation. we just snapped it in and out and got it with a stroller in a set for about 130. also so much easier when they are sleeping to go from car to house etc. anyway in case you can't tell, i highly recommend the graco. good luck with all of your decisions!