Is there any particular need for a large Vita memory card besides having multiple games and save game data? My Vita is coming in the mail and I already have a 4GB card I bought on clearance. I know I'll need to buy a bigger card at some point soon, I just haven't decided if I want a 16GB or a 32GB? I don't plan on storing music or videos on it, just game save data, DLC content, and items from the PSN+. If a game is added to PS+ and I download it to the card, then Sony pulls the game from the free lineup, can I still play it as a full if its sitting on my card?
First, with PS+ as long as you "buy" the game while it's free then it's tied to your account forever, even if your sub lapses and you renew at some point, but you can only play it while you have an active sub. This means you can also redownload it at any time as needed.
Second, If you're only going to keep one or two games on there at a time then no you don't need a big card. That being said I went with two 8GB cards initially, as in 5 days ago, and already returned them because of what a pain it was. On one 8GB I was only able to get 4 games, each about 1.5GB give or take a little, totaling about 6GB before I was out of space for another "full size" game. Not awful but was honestly a little surprised at just how small it felt once I did that. If you're really good about only playing one or two games at once and then moving on then you'll probably be good at 16GB, but almost everyone said when I was asking the same question that they ended up feeling pretty cramped over time. If you want 32GB Amazon has it for just under $81 with FSSS or Prime right now or you can try your luck on catching an Amazon Warehouse Deal on one for $60-70 but those have been snapped up in seconds lately.
TLDR: I tried to go the cheap route and realized how errant I was in two or three days time and knew I had to bite the bullet and buy a 32GB with this $7 4GB to hold me over until it arrives. At nearly $50, and the last few days closer to $60, the 16GB is the worst value of all the cards IMO. Just whatever you do don't do multiple small cards, it's a pain in the butt.