We had one of those handles for a while (until we caught the rope on the prop and it got eaten,) and I don't think we ever really had problems with getting blisters. It's got a pretty thick layer of cushy foam, and it doesn't cut at you like some.
Now we have a Ronix Moanna handle; the diamater is thicker and it's a straight handle of course, but again, it's pretty cushy and we haven't been having blister issues. The diamater might be a bit too much if your hands are small though, it's a bit on the big side, and it doesn't float, so that's annoying.
If gloves aren't quite doing the trick, you might try wrapping some sports tape around the area that's getting beat up; saw a girl at the cable park doing it the other day and she said it worked really well.