...with limited capacity. I can have a set ammount of VITA games on a memory card, but I can have just as many VITA cartridges/cards as I see fit, plus they are all branded and with their jewelboxes. It's like arguing that having a knife and a fork equals having a set of cuttlery in its designated box - you can still cut up and eat your meal, but the latter is simply more stylish.
EDIT: Ugh, Auto-Merge hates me. >>
You may only be able to store so many games on one memory card, but nothing stops you from carrying as many
memory cards as you see fit. Considering you can definitely store > 1 game per memory card, the number of memory cards required < number of individual VITA cards required. So therefore digital downloads are more convenient from that point of view.
However, factoring in the price of the memory cards, and the set price of downloads (as opposed to special offers etc. in stores and online for VITA cards), it may not be as cost efficient. Also, for those who have very slow internet connections, downloading huge Vita games (considering the size of a typical PSP game is 1-2GB in my experience, assuming Vita games will be larger) could take days. Also use up a large amount of download allowance for those with limited allowance due to pathetic ISPs.
In my opinion,
these are the factors that should affect a decision between physical and digital purchases. An instruction manual (which most people don't read) should not be the deciding factor.