Wow, what a difference this has made. On our '05 Vista (and most other HS tubs I'd guess) you can get OEM replacement rotary jets for all the "Precision Jets". These are the little jets that can get "itchy" after a while - the rotaries change the whole feel of the tub. I think there were 18 on the Vista, including the knee, wrist, and neck jets all around. I found 6 on Ebay, and ordered the rest thru my dealer. He'd never changed them so I just experimented at water change time, and found you twist off the bezel and the Precision nozzle comes right out, then use a small screwdriver to pop out the nylon bushing that holds the nozzle. The rotary then drops right in. Put a small dab of silicone caulk on the bezel before you twist it back on or it will vibrate itself loose. Dealer gave me "inventor's discount" since he didn't know about this - I told him he should have these as a standard aftermarket item (actually I emailed HS that they should put these in every tub). This is not hard to do - you are not disconnecting any plumbing.
You should also get rotaries for the larger directional hydromassage jets - especially the 2 in the lounge footwell. AMAZING. These just screw in/out. Have fun 8-)