Bullfrog makes a good product however many BF dealers try to demand more of a premium than is warranted. As far as water condition (smell) the answer is NO. The same water that circulates in the spa also circulates behind the jet packs. This means that the water back there isn't "stagnant" (as some dealers might try to portrary to the detriment of BF). Moving the packs is just as easy (easier) than taking out a filter. Since it's so easy to do, many owners DO move their packs. This is NOT what the major mfgs wany you to believe because the only way they can move theirs is one "jet" at a time and nobody is going to go through that much effort. Changing it in a HS could take 10 minutes whereas in a BF it takes almost 30 seconds. As far as efficency... The BF is foam filled so you get that benefit but they also use the move energy-hungery 56-frame motors so there goes some of that additional efficency so they are about the same as all the other foam filled in regards to efficency. I went about 85% of the way towards becoming a BF dealer two years ago. I agree that they have some great ideas but as with any small franchise, your expereince with them will be reliant on the dealer themselves. If you have prices, share them here and we can probably guide you pretty well. In short, you should be able to get the 651 for under $8K (they will ask nearly $10K for it but there is like $4K profit in there). And yes, the pumps do determine where you can place packs. The easiest way (more expensive) way around this is to simply put in the biggest pumps and that way you can pretty much move any pack to any seat. An underpowered pack WILL work in a seat that "appears" (by their configurator) to be underpowered. There's NOTHING "techincal" to stop you from building the spa ANY way you want. Many don't want all that power and once you get it you can play with the packs to see what is acceptable for you. In addition, you significant other can go back to the store next Christmas and buy you a different pack (or two). Good luck!