I like pool sand better than play sand. I've tried both, and the pool sand looks a little more realistic. The play sand has such a flat smooth color, I like the little specks in the pool sand. Waste also shows up better on the play sand, so it looks dirty unless you're extremely religious about siphoning.
Pool sand is a little larger, a mix of colors together, and MUCH easier to clean. I spent about 10 minutes rinsing enough pool sand for a 60 gallon, and about 30 minutes doing enough play sand for a 10 gallon. The bag of pool sand I bought was like $8 for 60 lbs, compared to play sand at $4 for 60 lbs. Not enough of a difference to justify the work involved in play sand.
Also, as they've already said, because play sand is so much finer, a lot of it will cloud up. If you have bottom feeders who dig in the sand, I'd definitely go with pool sand to save filters & prevent cloudy water.