The only negative was load times which are hugely disappointing. I wonder if that is the price to pay for flash distribution(have super slow chips to make the price manageable?). Are the load times any better if one buys the games from PSN instead of those flash carts?
Not all games are equally bad though. Wipeout stands out, but it has had a patch, and it caches a lot so that from race to race, the load-times are often halved. And of course the important part, restarting a race, is less than 10 seconds. Games like Uncharted have an initial load, but then while you are playing it's just like all the other Uncharted games, with almost all load-times hidden by boost-ups and silly stuff like that.
Plenty of other games hardly have any load-times.
What you do notice though is that even games that don't have that much load-times, because they often have an online aspect (leaderboards and such) there is some slight delay in that - Motorstorm, although it cleverly has plenty of async synchronising of cloud data and leaderboards and such, does still do a lot of online stuff and that does add a delay to games. Lumines has some of the worst use of this, and adds a lot of nonsense wait-times to retrying time trials, and it takes a long time to check your leaderboards (obviously for the main game it matters little). In that respect that bothers me more than the load-times in WipeOut, because that game gets pretty intense and I can use the breaks.
(already won the final race btw, but had to skip one and have some side-races still open - Sol is killing me, will have to work on that one a lot, hopefully having the Piranha unlocked helps, as it seems built for that track)
Mostly no complaints from me though and what really helps too is that you can do quite a lot of stuff while you have a game open, so that returning to the game is fast and easy.
I'm still extremely happy with my Vita, even if at times it makes me appreciate the PS3 more too. Some stuff is still ace on the PS3 - selecting Journey in your XMB and having the XMB transform in the Journey themed select screen so smoothly and with some nice details (like the regular text behind the icon disappearing), but other stuff like messaging and interacting with people using near is just fantastic, and surprisingly looks beyond even what iOS does. It stands out all the more because you have the same messages on XMB and it just looks vastly different. It makes my mind boggle to think how much better the console user interface can be if they apply some of this stuff to there and give it some more breathing room, but the advantage of a touch-keyboard on the Vita isn't to be overstated. I can definitely see why a touch interface on a next-gen controller would help a lot in that respect.
All in all though the Vita is pretty close to my dream portable (within realistic limitations of course). If PS Suite becomes what I want it to be, and they add some more features like Video streaming and such, then it's more perfect than I'd have dared to hope (camera's could have been nicer though).
Even the memory cards - the idea that I would buy a 16GB iPad 3 today and be stuck with 16GB forever is crazy, and the markup for 16GB more is as much as a 32GB memory card for the Vita costs today. It is very comforting that I can at least hope that by next year I can stick a 64GB card into my Vita for, say, $50, and that can keep scaling up for the lifetime of the Vita, bring more size and better speeds. Of course I don't have a guarantee - Sony can keep this closed down and small - but I don't think they will.