Which manufacturer makes the best engineered tubs? Marquis, D1, Bullfrog, other?

[steel_3d]

Yeah, I think I remember the salesman calling them HK.

[MarKee]

Yes, most Marquis Signature Series models have the HK40 (40 gallon per minute) jets.  Some models also have geyser jets for feet and back in some positions that put out 60+ gallons per minute.