I haev used all of the above, but the u-pol. 3M is the best, but it was $10-12/can. The ACE hardware version is OK (price ws ~$6-7). The NAPA (Williams-Seynor--or something like) is OK as well and was also reasonably priced. If you are only going to be doing a few small important projects, go with the 3M. IF you are going to be doing alot of work, then go with one of the cheaper ones. I do remember the 3M going a long way, moreso than the others.
Good luck.