One thing I immediately noticed upon enabling Windowblinds 10: it drastically reduces the smoothness of the desktop rendering.
I have a 144Hz LCD (kept at 120Hz most of the time), and moving windows around is super smooth. If I enable Windowblinds 10, the movement of windows becomes quite rough, as if the framerate is low and perhaps actually uneven. At best, it feels only as smooth as the default theme at 60Hz.
I value the smoothness much more than I value the customization, so for the moment, I've switched back to the Windows default theme.
This shouldn't be a matter of insufficient horsepower -- I have a Radeon R9 290 and a Xeon E3-1245 v3 (3.4GHz).