I would go to Target and just look at the seats.

What about the Chicco MyFit Air? No direct experience, but might be more comfortable for a kid who runs hot.

We have the Britax Grow With You and have no complaints. My kid has a big head and doesn't have issues with the headrest. We were limited in our selections because he is super tall and Britax has one of the highest height limits for harness mode. It's the easiest to install seat I've ever used.

Anyone love their harness-to-booster carseat and can offer a recommendation? Or hate it and can share why?

Our kid is in a convertible car seat, same one she's had since she was a year old. She still technically fits into it (for both height and length) but it just doesn't seem like a great fit anymore and it looks like a harness-to-booster makes the most sense as a next step since she could use it as a high back booster and maybe even a regular booster for many years. But I can't find as many reviews and comparisons on this class of seat as I can find for regular convertible seats and regular boosters. I can find individual reviews but they don't compare to other seats.

I did find one ranking (from Consumer Reports) but two of the recommendations are budget picks and the other two are the Britax Grow With You and the Graco Nautilus, which have some of the same design issues that are making the current seat uncomfortable for my kid (namely, their head rest is a bit small for my big-headed child, and the fabric cover and design of the seat makes her really hot on long car rides, even when not in the sun and with AC on full blast). I'm curious about the Graco Tranzitions and the Diono Radian 3R but can't find a ton on either seat online.

Any recommendations, warnings, guidance, etc. would be helpful. TIA!