I just have little to no faith in play money tables as a learning tool beyond the absolute basics of game understanding (how blinds work, etc.). Unless, of course, you can find some sort of private league that plays often enough and keeps track of performance. I'd focus on freerolls and take that money to the single table SNGs. As long as its not your money, and you are focusing on improving your game, put those winnings to good use. I know a lot of players that started as freerollers and are now internet monsters with big bankrolls. Takes time and a lot of practice, but you can do it.