The windows 7 has a bit better distinction for groups and such in the events sheet, so windows one for me :)
I think there is a problem with construct and the color changing in the beta.
I never experienced construct 2 laggyness like I did after changing the colors.
some of the side panels suddenly slide open very very slowly after setting a color scheme (closing and opening construct fixes that) But it doesnt happen everytime.
I just noticed the laggyness once I started fiddling with the colors.