Somehow, both. In WCW, as The Natural, he was pretty over and seemed like he was destined to be in the main event at some point. Probably for a while (2-3 years, as a #2/3 babyface depending). He never took the next step, which seemed so logical at one point that it was all but set in stone in some people's minds. Really, who expected Diamond Dallas Page to be a main eventer and Dustin not to in the early 90's? Crazy.
Then he went to WWF, where the good 'ol boy look means squat in comparison to WCW's demo, AND is given a fruity gimmick in the midcard. I all but wrote him off, but he really embraced it and took it as far as anybody could. Then pretty much fizzled out because Vince won the war and totally gave up on the midcard, so he gets electrocuted and stutters.
Got further in WCW, but he should have gone further than he did there. Then in WWF, he over-achieved given his gimmick, crowd, and low spot in the pecking order.