Personally I love the idea, but my first and last experience with one was... Scary.
This is coming from the perspective of a man, but they feel pretty good - but I'm not sure if this was just the pressure on my prostate or just the full filling, so take from that what you will. Regardless, if you decide to go with one, here are a few pointers.
-Don't cheap out. Really, don't.
-Go slowly, both in pumping it up and each session using slightly more pressure.
-Don't go overboard. Some people can pump them up to their max, but I'm sure it took them years to get to that point and I personally don't see why they do it to begin with.
-This really needs to be repeated, don't go overboard. Start off with a few pumps, then during the next session add one or two more.

Wish I could be of more help, but that one time I went overboard was probably the last time I will ever use a pump. Scared the hell out of me.

I bought this one: link (Gapers Organic) and I really love it. I'm not new to anal play or plugs, but not an expert by any "stretch" of the imagination. I only have to have one or two full bulb pumps and it's more than enough for me. This toy has a nice velvety feel to it and it's fun to have inserted, too! The only thing I don't like are the ridges in the toy's outer coating with regards to cleaning - you have to make sure that you use soap and water and get each one cleaned well - although you can do the dishwasher thing, I feel that doing it by hand with a washcloth and mild soap w/ water is better with non-smooth surfaced toys.