HBB or LBB for tall 8 yo?

[mommybug]

DS1 is 8 and 55 inches tall. He was in a Harmony HBB in our Prius but it looked like it was getting too small so we just switched him to a LBB. Should I keep him in a LBB or think about getting a bigger HBB, like a Cambria? The Prius is so small and I just worry that he won't be protected enough if there is a side impact collision. In our Odyssey he sits in the middle seat of the second row in a Turbobooster. Should I move that to the Prius? I want to get a booster with LATCH for the Odyssey because the narrow middle seats means that the booster wobbles a little. I'm hoping that using LATCH with resolve that issue. Any recs for a LBB that has LATCH?

Thanks!

[Joolsplus2]

Backless is statistically just fine, nowadays (high back used to be better, funny how statistics and side curtain airbags work! http://carseatblog.com/8243/to-backl...-the-question/).
If you want a great big long lasting booster for long trips (or if he's a major car sleeper?) and comfort and LATCHing, then the Cambria might be a great choice (or Recaro, both seem to be super awesome, but my 55" 8 yo is in a backless happily so I haven't been compelled to purchase one myself, lol...)

[mommybug]

Thanks, Jools! He never falls asleep and is happy in the backless. He actually likes the Bubblebum, but I don't like how much it moves around. I think for now I'll move the Turbobooster to Prius and put a LBB in the Odyssey. I picked up an Affix LBB since it LATCHes but then I saw that the max height is 57". Why is there a max height for a LBB? I'm also going going to start a new thread about that...