When my son was 5 months he had outgrown his infant seat. We bought a Decathlon for my car. I really like it because it has a 3 position adjustable crotch strap. Immediately he was at the farthest out position. About a month later when we were deciding on a seat for my husband's vehicle, I bought a Boulevard. When I got it installed & got the baby in it, he was sitting on the crotch strap, & I couldn't get him buckled in. The crotch strap is NOT adjustable on the Boulevard. So I had to take it back & exchange it for another Decathlon. We are so happy with them. The thing I liked about the Boulevard was the height adjuster was on a knob, for a quick, easy adjustment. If the crotch strap was adjustable, I'd be sold on it, but it just didn't fit his front to back width. Especially with any bulky clothes on (this was in December.) Hope this helps, and you are 100% happy with whichever seat you decide on!