I researchedand chose this booster seat because it is one of the widest ones out there. A lot of kids that are more on the "thicker" side have a hard time fitting between the armrests on regular booster seats before they get tall enough to not need a booster seat. I had my 11 year old who is 57 inches tall and 110 pounds sit in it, to make sure it would really last as long as I need it to for my 5 year old. He said it was comfortable and fit him well! I am 5'1" and I tried sitting in it, but the highest head position was too low for me, so I don't think it could really work as a high-back booster for children up to 63 inches, but you can also take the back off for taller kids. I had trouble installing it at first and had to adjust the seat recline and headrest a little on the actual car's seat to find the right position for the back of the booster to line up correctly with the back of the car's seat, but it wasn't too hard. Ones you get it right, hook the LATCH connectors and put a knee in the seat while pulling the straps on the front of the seat to tighten up the installation.
I took off one star because when I opened the box, I couldn't figure out what the terrible smell was. It's kind of like old cheese and dog. I think the box must have been stored somewhere stinky next to something stinky. I don't think that all of them have that smell, because the display booster seat I saw in a store didn't smell bad. I'm giving it a few days to see if the smell disapates before deciding whether or not to return it.