Convertible car seats

I have twin boys who are right now 4 months old.  There is a great deal going on at Babies R Us that you can trade in your old baby gear and get a discount on some other type of baby gear you may need. Ex: infant car seats trade in for a discount on a toddler car seat.

Now of course my boys will be in thier infant seats for some time still. We have 4 infant seats, due to the fact that the hospital would not release our boys from the NICU in the seats we had bought for them. They were these really nice Graco seats. The boys were too small for it. So at 10pm on the night we are to take them home, my wonderful husband had to go out and buy other car seats. So we only used the other car seats for about 2 months and then the boys were big enough to fit in the ones we had originally purchased. So basically we have 2 extra seats.

I would like to know what your opinion is on convertible car seats. Which one do you think is the best? What has worked for you? Any suggestions would be great.

Thank you! Sara

we have one now i believe it is a graco seat. we love it and plan to use it for our next one (due in June) when he or she grows out of the infant carrier.