I don't think I'd mind doing a short term roleplay, except that, due to my inability to let things go if we don't make a decisive ending, I'd probably wind up making it long-term anyway. Which defeates the purpose. I found myself reading and going, yeah, short-term would be cool, small scene of a bigger story, just pick and choose the parts you like and want to play out, toss the others... Then I realised that would be a lot more work for a supposedly shorter rp that could, potentially, go on for as long as either partner is ok with. Soooo, not really short term.
I have done chat rps, but I do prefer, again, that they have a wider context, which would require plenty of discussion and build-up. I like the fast pace, but I don't always have the time, and I find there's less connection between the characters and definitely more chance for me to mess up characterisation.
The one time I think I managed to do something short term, was my sister and I passing a notebook back and forth during exam prep(yep, we were totally using our time wisely, we also made father's day cards while we were there >.>). I think I was alright with that because I knew who I was writing with and we both knew each other's style and could quickly and easily guess what would and would not work with our preferences. So, I'd be down for trying a short-term again, certainly, but I'd probably want to know my partner, and I'd probably prefer that it be a quick little aside of a larger story we're working on. Maybe going, y'know what, I liked that NPC, can we flesh him/her out more in a little side thing when we've got the time? Just a day in the life?
An actual one-off, short-term roleplay where I don't already know my partner or what we might be writing, I'd still be willing to try, but I do definitely prefer long-term stuff. Investment-wise.