Not that I'm an expert on the touhou fighting games (or japanese for that matter...), but 1.11 does mostly seem to be bug fixes-

- aesthetic changes with the spell change effect, mysterious spot, occult aura, popups etc. (the mysterious spot name popup is shorter and becomes transparent faster)
- fixed crashing on windows vista ( :V)
- fixed a bug from changing the time on the pc
- lots of fixes in regards to network play, including battle statistics, lobby and opponent pairing, being able to save replay even when online match is interrupted
- being able to change window size using ctl-alt-[1-4]
- fixed some problems with colour changes
- fixed Mamizou's capsule opening motion not scaling when in high-air or low-air
Unfortunately I'm not familiar enough with the game to figure out what other changes are, minor corrections to Byakuren's and Mokou's moves, but they don't seem to be gamebreaking