Coastflyer,
My choice for the lower end wind kite is definitely Rhino.
I prefer the fast and grunty kite for lower wind days (it's more fun and easier), and slower and softer kites for not so pleasant high wind days. Anyhow, Rhino is designed to prefer the lower end and Rebel does high end. So you will probably get more wind range out of Rhino in a light wind condition.
Currently I am riding 07 Rhino 12m for the light wind days, and I have written my name all over the kite meaning I will never sell it! I have not yet tried 08 Rhino, but I can not imagine how a kite can be better than the 07 performances. This model is definitely setting the standard for my future/current kite choices.
In regards to the bladder issues, North had recalled kites sold till mid 2007, and anything sold after the recall the 2 pump system should not have any problems. Mine works fine and never had any issues. In fact, due to the recall history, exchange rate and 08 introduction, you can now get 07 cheaper as a new kite price ever gets, and recommended to grab the bargain.