Builder grade and contractor grade are interchangeable.
One thing to check is that the machine is leveled properly. If it’s not, the frame will flex and cause leaks.
I have a GE Quiet Power 2 dishwasher that I bought second hand 5+ years ago and that thing has been rock solid. All I’ve had to do is replace the plastic strainer on the bottom with a stainless steel one after it warped from being close to the heating element, and replace a rubber hose going to the pump after a mouse ate a hole in it.