I drag them around... but i am not looking forward to the day the legs break and fold under the cabinet.
I think it would be very difficult for that to happen. The gauge of steel on the legs is quite thick, coupled with the L-Angle + the strengthening ridges = You would to work to just bend them with a sledge hammer.
The weak point is the actual cabinet mounts. If the legs are not bolted tightly, missing bolts, stripped out threads..etc... is pretty much the only likely fail point. The cabinet itself would fail before the legs... and the cabinet is no joke either.
Personally, most times I just get under the machines, and raise to a crawl position, walking the thing on my back with one leg set sliding lightly.
Long distance is different. Thats a slow slide job, or two person lift effort. Or pinball lifter if its available.
Remember, pinball machines are built to be abused and rocked around like crazy. Anyone who doesnt even bump the machine, isnt playing pinball correctly.