I do not care for the Britax seats (probably same kind of laungry lists of just things that apply to me that you have about the Titan) but I have a LARGE 2 year old. He's 42 inches tall and 42 lbs. SO, I needed to find a seat that would keep him harnessed for as long as possible, and hopfully transition to a booster. We bought the Graco Nautilus and it is AMAZING. Since he's grown so much since birth (and we really weren't expecting him to, ha) We've been through a lot of car seats. This is, by far, our favorite. We are even going to buy another one to replace a perfectly safe car seat in our second car because this one is soooo much better. We have another seat that can be used with the harness until 65lbs and it's HUGE. Similar in size to the Frontier, but my son has more wiggle room and seeming comfort in the Graco Nautilus. The best part, it doesn't matter whether we have the seat in my car (Ford Explorer) or my husband's (Ford Focus) because it seems more compact. It sits up higher and my son loves it because he can see better. Anyway, my advice is the Graco Nautilus (harness to 65lbs, then a booster with a seat back, then a backless booster, yes its all of those things...truly, not like some) Good luck.