Before I answer your question, I just have to ask......Did you even bother going to google and searching around a bit? Pro= 475mhz and 12 pipes XL=400mhz and 16 pipes XT=500mgz and 16 pipes So it's realy subjective to what you need and are willing to spend.
Thats a nasty comment. Thats the beauty of Bit Tech forums. If theres something technical you need answers too then there is someone willing to help. What else is the foum here for. You just like to flame, dont you?