I haven't worked with instant film in ages. Well, that is sort of a lie. The more accurate statement would be I haven't worked with integral instant film in ages. I've worked with plenty of peel apart fuji pack film over the years but by and large ignore the integral film (i.e., the stuff that spits out the front of the camera).
I think the biggest reason I tend not to work with it is because of the cost. The only film still available is from The Impossible Project and it isn't cheap! However, while buying some paper from a local camera shop the other day I just got the urge to buy a back and have some fun with it. The very next day there was some lovely light coming in the bedroom so it just made sense to pop off a few frames.