I've had the worst nightmares playing out on other people's 1200's more then once - really low torque, you match the beats painstakingly over half the length of the track, press stop button, then start again, and it starts a few % slower all over again. Unfortunately I found people often don't give a shit about routine maintenance of their technics here, especially if they have a pair that they don't mix on themselves but only give out for rent to parties.
Happy with my numark ttx1's mostly, but unfortunately as well found a very common issue with them - start/stop electronics fuck up and you need to replace one chip. I had it on one of mine, a friend had it on his, another guy I know had this, but I did not find any mention of this with other users on forums etc.
Bottom line is - either do good maintenance of your trusty old 1200's or go for newer brands for more featrues and higher orque if you're ready to put up with some shit that may come up.