I have to say, having a PSP CFW on PS Vita may be nice, but you lose access to many sales, currently many Japanese Vita games are on sale in the European PSN store, online gaming and newer games that are already released or will be like World of Final Fantasy, Danganronpa 3, God Eater 1+2 and so on.
Native PS Vita homebrew isn't that great either even though the effort put into it is impressive.
If you want to play PSP games free, use a PSP, it is completely compromised, installing CFW is easy as pie and you can use custom servers to play popular online games and even some ad hoc games online with it.