I see nothing wrong with checking battle files AFTER the match to check if someone really did cheat (sometimes its hard to tell if someone is running triple pershings when they got dual repairs) and a lot quicker then watching a replay.
That being said, it is cheating doing it before hand and generally you can get someones company composition just by asking their last opponent.
Lastly to finish the threads title.
"I do not check battlefiles,
but when i do, its to make children cry."