Tried the smaller "Zengina" 
which worked reasonably well before I was pregnant. Cannot get on with it since I had my baby, though - it's all just a bit different down there and there seems to be less room rather than more which is (a) not what I expected and (b) not actually massively convenient. Tampons still work perfectly well but I hate the expense and the environmental impact (currently using TOTM tampons but you still have to buy them and they're still single use). Reusable pads aren't great as I'm cursed with sensitive skin and also very bad at keeping up with laundry.
Would very much appreciate any recommendations for smallish comfortable cups!