well the monitor itself is a great monitor. the picture is (read: can be) great, its just plagued with a few problems.
there is a few caps that need to be looked after. if its working right now, it would be VERY beneficial to change them before they fail and you have yourself a real issue. like the dude from wells gardner says, if it breaks down, it takes a whole whack of parts down with it. and generally it starts with either a faulty cap, or a blown HOT.
if you don't mind babysitting it, and regularly checking it every month or so (if your leaving it on), then it's fine. if you are only sporadically going to use it, it's fine too. but if you want something that you can stick in there and never have to worry about it again, it's probably best to look at something else.