I'm always annoyed when someone does this to me in a 'won' position but I must admit I do love it when I can save a draw by using it (not as often unfortunately)
I understand the OP's frustration though regarding it as cheap, it does almost feel that way but it is part of the game.
Some TT puzzles are centred around this and you have to choose the right move to stop such delaying moves.
Opponent is very much within his right to give u perpetual check.U can'tdo anything about it.If he gets away with it (either force a draw or waste time)it is his plus point and your minus point that u failed to notice this before and take this into consideration before the perpetual check
started.