best booster

[jen28]

we are getting ready for some summer travels and i don't want to bring my large britax seat so i'm considering buying a booster for my almost 4 year old. what do you recommend?

[Joolsplus2]

Do you want a dedicated belt positioner (no harness) or a booster with a harness (combo seat)? How much does she weigh? High back or no-back? Will you be in the car alot? Is she a big car-sleeper?
I'm traveling now with my 4 yo, and I keep kicking myself for trying to make her sit in a backless booster and wishing I had the fortitude to bring the Marathon... :(
Julie CPS Tech and mom to 2 in seats
http://www.cpsafety.com/articles/RFAlbum/SarahMA.aspx