Haven't stayed Harrah's in a long time, but a room in the Mardi Gras tower will insure that you aren't overlooking the Carnival court (is that even still there?). I forget the name of the other floor, but a high floor there would also probably take care of the noise problem.
The executive suites are very nice and on high floors, so that would reduce the noise potential (have stayed in exec suite x 2 and no noise at all). They are actually true suites with actual separate bed room and living rooms, baths, etc.
If traveling with someone else, or entertaining friends, the $49 per night might be worth it.
If it is just you...well, that is up to you, but it is a lot of area for one human.