Dave,
I haven't gone over to sign the papers yet on my first spa, but I have spent a ton of time trying to sort this out. I'm sure that it will be time well spent when I can take my first dip in my own tub however.
A couple quick thoughts that I think many of the experienced members on here would tell you.
Don't get hung up on the bells and whistles of a stereo system, waterfalls, misters, aromatherapy,etc. In fact I would try not to let these options enter your mind as you narrow it down. Research this forum, find the most respected names, find their local dealers, go look at the tubs, evaluate the "trust factor" in your dealerships, consider warranties, wet test. Actually a great place to start would be to read a couple really good posts started by ZzTop - "How to Negotiate and Buy a Hot Tub" and "When buying a Hot tub what is most important?". Both we just posted within the last couple weeks.
Good luck,
Buckeye