I've been using it for about a year now and LOVE it! It's so nice to only deal with it 2-3 times a day rather than 4-5 times like I had to with tampons.
As far as the public bathroom comment, I just try to make sure I won't need to change it when I'm out.
There is a learning curve in getting used to it, and for the first couple cycles, I wore a thin pad or pantiliner just in case. I also had one cycle that I just couldn't get it and had to go back to tampons. It was horrible! Sure reminded me why I switched to the Diva. I haven't had a problem since that one time.
I got mine at drugstore.com, and was able to find a code for money off, and then free shipping, so it was very reasonable. Especially when considering I haven't bought a box of tampons in a year!