Really, anything that you use that ISN'T your Pokemon game (or anything else that is not LICENSED or ENDORSED by Nintendo) to get items/Pokemon/events in your Pokemon game is cheating.
Obviously things like distributions from GameStop or getting a Pokemon from a trade is fine- trading is getting a Pokemon from another game legibly, and the distributions are Nintendo events.
-So it would be bad to use PokeSav/Pokedit Pokemon in a tournament.
You are using these things to generate the Pokemon you want without working or breeding for it.
By no means am I chewing you out :p I enjoy messing around with this kinda thing for fun, but obviously don't use them anywhere but in-game.
See what Nintendo says about cheating here.
They mention not using these Pokemon at official events.
Hope this helped :)