I've got a 32GB card which has on it:
-Uncharted, Disgaea, Everybody's Golf, Wipeout, Dynasty Warriors, Ninja Gaiden and that freebie puzzle game on it Vita-wise
-Persona 3, Spectral Souls, Tactics Ogre, Gods Eater Burst, Z.H.P., Harvest Moon, Dissidia 012, Disgaea Infinite, Zenonia, Numblast, Urbanix and Jewel Keepers on it PSP-game-wise
-a few of those free apps
-a bunch of anime episodes
The card still has 10GB on it apparently, which seems pretty reasonable considering the amount that I have on there, a lot of which I could easily take off if space became an issue. The only physical game I own at the moment is Shinobido (the save data is on the card so it's not going anywhere!) and I'm really happy with this setup.
If I want to buy a Vita game that has replay value like the ones above then I'll probably get it digitally. I'll probably save my card buys for import games, games I'm not completely sure I'll like or ridiculously cheap offers.
This is partly influenced by the fact that I traded in a crazy amount of old games a little while back and ended up with over £200 in PSN vouchers though.