My Spa Crest hot tub is the most unreliable thing of any type that I have ever owned -- and that puts it below the 1953 Chevy I bought for $25. During the three years I have owned the spa, I've been able to use it no more than a dozen times. The spa is operational no more than 10% of the time thanks to electrical failures -- which scare the devil out of me -- and plumbing failures. Just keeping the water chemistry balanced is a challenge, since the water circulates only a couple days per month.
Most recently I went to climb in and found it half full and shut down. This time a piece of pvc plumbing that passes through the spa shell had sheared off and a hundred gallons of water had poured onto the electric motors. This is approximately the tenth time that plumbing and seal problems have drowned the electric motors and put the spa out of commission.
I give Spa Crest an F for materials and an F for workmanship.