It definitely isn't, I know people who have watched it 7 times already lol. I would recommend watching it in regular after you've watched it in IMAX to really understand the story. Also it saves a few bucks.
Yeah, all the corny scenes and cheesy lines you claim there was, watch the regular showing and that'll all just disappear for you. If you watched the regular showing first, then watch IMAX and the same thing will happen.