Moving on up to Harness Booster - looking for advice

I haven't been here is so long!! My 4.5yr old has been happy as a clam in a Britax Boulevard 65 RF since she was 9 months to 2.5yrs and now FF the last 2yrs. She still fits in it, but she is almost 44" tall and 44lbs. I do not know her torso but I feel we maxed out at the top of the seat thread (it won't roll any higher) and she has about 2" at the top of her head. So the time is coming soon.

We have a 2011 Toyota Sienna with bucket seats 2nd row. We also need another seat for a 2nd car, it is a 2008 Jeep Grand Cherokee.

I am loving the Frontier but just want to be sure this is going to be a good seat. The crotch strap is very important because right now, the Boulevard is getting behind her which is the main reason I want to switch now instead of waiting.

I was think the Nautilus but I remember awhile back that being an issue. No crotch adjuster. Is it the same?

And from some quick studying it looks like the ProSport is popular too but I know nothing about that seat.

I just want one with a good buckle, comfortable for a girl that is big for her age (95% for both) I don't want it too narrow. I do not have her torso measurement but can get once she gets home from school.

It does not have to convert to a backless. I can get them later down the line.

Thanks in advance!!!

The frontier90 is the tallest which means it will last the longest harnessed, it also has the most crotch room. Its very wide and the headrest is quite a bit taller than the kiddo so in some vehicles it wont adjust to its full potential due to the roofline.

The prosport (or performance sport) is shorter in harness height but is narrower and has a more "efficient" headrest.

The nautilus can be tight in the crotch area. Is the same height as the prosport but does last the longest as a booster (since it goes backless.)

All three are great seats but I would probably go with the frontier for a kid with those stats.

I would also suggest the Frontier 90 there is a very nice review on the blog. My 4 and 5yr old have similar stats as your DD and they are both very happy in the FR90.