I cannot impress upon everyone just how horribly horrible the horrible Synapse 2 driver software is.
Macros disappear into the ether, it asks for your administrative password at every startup, it freezes everytime you wake your computer up from sleep, memory leaks like crazy, and causes problems when it can't connect to the mothership. This is for the Mac version, though I've read plenty of complaints about the Windows version too.
Plus the keyboards are pretty low quality when compared to other mechanical switch keyboards. The keystems are, for some reason, shorter than normal so they wobble considerably more than the same switches on other boards. Bent backplates and keys that rub each other or the frame are common.
I like their mice, though.