I picked the wrong cup at first, but customer service helped me find the right one for me.
I ended up getting the small soft cup. After trying their standard firm cup and having issues with it, their customer service was very good and helped me pick out the cup I use now which works really well for me and is far more comfortable than the first cup I tried. I'm really glad they sent me a new cup to try so I didn't have to buy another one. The only thing I think could be improved is the stem of the cup. It is very thin, and a bit slippery and difficult to grip.