I am a complete newbie to this topic, but I have been doing a bunch of research on convertible car seats for my baby boy due in the next week or so. Obviously, safety is my top priority which is probably the case for every parent. We got two car seats for the baby shower and I returned them both because I wasn't sold on my initial decision. We are starting off with the Chicco KeyFit 30 in my wife's Nissan Murano 09 and I drive a Civic 06. I read some older forum posts and many recommended waiting for several months before purchasing any convertible car seat when your child hasn't arrived because they expire. My research initially pointed me towards the Evenflo Momentum 65 DLX and the Britax Marathon 70, but I am kind of weary about the Marathon after reading about the toxic reports from WebMD. The more forums I read, the more recommendations I saw for the Complete Air 65 which wasn't even on my radar, because of its longevity. So, would I be best served to sit tight because these convertibles seem to change so quickly? Also, I haven’t seen much feedback about the Momentum 65, but it rates out high on CR & NHTSA. Thoughts on the Momentum compared to the Complete Air would be appreciated?