Also being a pro-gamer in RTS years ago, I can relate. There are many small steps between n00b level and mastery and a lot has to come together to be at expert level in gaming. Usually experts can play in variable settings, cheaters only in one particular. Experts can adapt, while cheaters usually not. Usually real talk about how you handled and interpreted a certain situation will show the difference. Cheaters usually are not the most talkative.
However sometimes there is a make or break in a certain game. While cheaters are usually spotted in the long run, it spoils almost every time the fun in the short run.
Missed opportunities to tourney advancement, frustration etc. can make or break players. Are we talking about the true winner, Carl Lewis, in the 100m finals in Seoul in 1988 or Ben Johnson?
I saw some guys with really good potential leaving out of frustration and that is really sad.