Theres some bugs, yes, but a lot of people blame Windowsblinds for stuff other software probably caused.
I heard if you use classic shell with Windowsblinds it can cause some problems, but isn't it obvious to not use two different customisation softwares not made by the same dev that may conflict with each other.
For me, Windowsblinds has worked well, the only problem is, I'm not sure if I should change to curtains.