This is great. I have been waiting for this for a long time, and all I can say is you've done an excellent job Geiger (Chickenlump and JLukas too). Packed full of new features and optimizations, you guys can give yourselves a pat on the back.
A couple of questions I've always been a bit confused about:
In the tile swatch, there appears to be duplicate tiles that TF reports no difference between, why is this?
And also (please ignore my ignorance) what exactly are subtiles?
Again, great work.
EDIT: Oh, in case you didn't know, the difference between "Play Sound (18)" and "Play Sound (19)" is that one stops when a new sound is played, while the other keeps going.