Well after performing an upgrade from 9.1 mine rebooted and then just hangs right at the start of the POST screen. Rebooting cold, nada. Even if I'm able to catch it quick enough to press DEL to enter setup, it says "Entering Setup" and hangs there.
If I pull the USB stick, then it boots as normal.
Edit: So I downloaded the Full v9.3 ISO for a fresh install. It sees the (new, formatted FAT32) USB stick. I start the install and then... nothing. It sits there doing not a thing.
Next, I downloaded the full v220.127.116.11 ISO and did the same thing. Now with the same USB stick as the target (reformatted again because something was written to it), the installer again sees the disk. But this time the install starts and it is proceeding.
So after careful consideration, I've come to the conclusion that v9.3 sucks.