When our second child was born in 2002 I purchased another Roundabout and have been equally pleased with this one. Another huge bonus is that these Carseats are approved for use on airplanes. I do not travel by plane frequently but had to on short notice and was pleased to find out my Carseats were accepted! I have heard many stories about people having to buy additional seats because their's were not approved - so if you do travel by air these seats are an even better deal!
My son hit 40 lbs in late 2004 and I purchased a Britax Marathon which will take him through the rest of the carseat phase; he was excited because Britax had so many different seat patterns and he was able to choose the one he liked. Also our third child was born in January 2005 and he now uses our son's old Roundabout. It has held up wonderfully even after many many washes it is stain free and the seat is as safe and sturdy today as it was in 2000 when I bought it!
I have had absolutely no problems with the three seats I have purchased so all I can do is give you the pros.
1. Britax are much more comfortable than other seats; they have thick padding and soft beautiful fabric covers. We travel by vehicle alot and my children love these seats and sleep easily in them.
2. Safety: Most Carseats have a flat back or slight curve on the sides of the seat. The Britax seats have distinctly larger side curves that almost conform to the child's body. You do not have to worry about your baby's head and/or body slinging from side-to-side plus the sides are padded too.
3. Harness: The straps are great. The five point body harness is wonderful but Britax has the snap at the chest/underarm level and the snap at the bottom. If you have an escape artist child in your family you will appreciate that this seat is more difficult for a child to unbuckle.
4. I cannot say enough about the Lower Anchor Tether strap - get a seat that has one and use it! If you just go to a store that has one on display you will see for yourself.
I know the Britax seats are expensive. Roundabout's retail for $199 + tax and Marathon's for $249 + tax. If you research you can find some great in-store sales or internet sales that offer free s&h. Also, I've seen brand new Britax seats go for amazing pricing right here on halfvalue. If you are going to invest money in one thing I would, without a doubt, say buy a good carseat. Accident's do happen and having a safe Carseat, properly installed and buckling your child every time could prevent a horrible tragedy.

