Adding the word check, feels a bit the beginning of turning the game from something we can use for proper competition, into something that is strictly just for fun and not serious at all.
That's the whole reason I play games for fun. I love the checker and that it can be turned off. I know if someone turns it off that I am not the type of player they want to play with. I am a terrible speller the pressure of trying to spell a word quickly while someone is watching is not fun. Makes me feel very stupid. Instead I do a quick check and know right away if I am wrong.
Maybe you feel it's cheating but I feel it's fine. I am already going in with a handicap because I won't get to long word bonus because I am a terrible speller. So at least let me take the pressure of by checking words.