So recently i've hopped back on the program and version 5 has made some leaps since 2011! So far i've been able to create a decent level and import my meshes from Silo 2. Back when I first used this you had to covert the files just to show up and pray that they weren't messed up when dragged to the scene screen. Now it's just accepting them like nothing :)

:D it's awesome that Unity keeps on being such a strong player whilst providing more and more for users who need not pay anything. What sort of game are you making?