Poor build quality
Driver issues that interfere with regular usage
I had an Asus TP-500LN because I wanted something that can do everything. After updating to Windows 10 it would hang on sleep or shutdown, forcing me to press the power button for ten seconds. I couldn't fix it, and eventually traded it for my gaming desktop in my signature. That had some annoyances getting the front USB headers and ethernet working, but it's fine now.
I also picked up a dirt cheap RCA W101 V2 as a portable, and it works perfectly. It does have the annoyance of the screen going sideways when redocked, but I just enter the shortcut to fix it and it's fine.