I play it once in a blue moon on a server that is whitelisted. Only time I bother playing it now though is when I'm so bored that sticking my head in a blender sounds fun. Then I boot up MC to creative mode just to play around with build ideas before I get burned out after about an hour and go back to coding.
I think you meant to ask how many slots it has, which is 20 by default. Note that e.g. ops don't count toward the limit in some cases, so more than 20 people can be in a 20 slot server.