Performance and reliability depend on the equipment used, not the physical hot tub that they’re installed in. 

Hot tub equipment consists of pumps/motors, heating elements, thermostats, motherboards, topside controls, transformers, high limit switches, pressure switches, probes, ozonators, lighting systems, blowers, UV systems, LCD screens, salt generators and a zillion other bits and pieces related to a hot tub’s functionality.

Some equipment is significantly better than others.  Sometimes there are cheap/generic parts that technically still do the job, but they won’t perform as well or last as long.  Cheaper parts may be a good choice for repairs down the road to keep the cost down, but it’s not a good sign when they come straight from the factory with cheap equipment.

The performance differences between higher and lower quality equipment may be noticeable immediately in some cases, but the reliability may not become evident until later on.