Except for a few driver issues, (Nvidia and Optimus, doh!), I haven't had a issue with Ubuntu or Mint. Any other issues with configuration, I would have also had with Windows or OS X since they were application or server specific.
But I don't spend days tweaking the UI, I have a baseline of UI expectations that's not too difficult to meet. (But Windows 8 doesn't meet it... 'nother story for 'nother day...)
I've had tons of issues. Especially around power management, multi-monitor support etc. When I "Hibernate" I also need to roll a d10 to know if it'll actually come back up. This is anecdotal but on same hardware there are no issues under Windows and everything works as expected. Eclipse seems less stable and slower under Ubuntu which is probably related to the Java run time. Firefox also less stable. Webcam sometimes doesn't work. Audio suddenly stops playing until you touch the volume. Couldn't get WebEx working under Ubuntu (tried lots of suggested workarounds). The kind of stuff that just works in other OSes.
I have the same issues on an Asus laptop. It was well supported on 12.04 LTS but the 12.10 is obviously a big failure.
Not to speak about the system that slow down by itself, some swap mess I don't have time to fix, and the overall growing instability of the system tools. Memcheck segfault, then the report tool activate itself, inspect, segfault, launch again...
I also upgraded a pc of a friend from an good old athlon xp to a new shiny i3, and guess what the official, libre, graphic driver is just unable to run correctly, apparently because of a bad switch in an internal opcode.
Something is wrong here. The massive shift of devs from linux to OSX should warn some people somewhere about the overall quality of their stuff. A quality that we have been proud for decades.
My printer, scanner, graphics tablet, and sound card won't work in windows (the printer manufacturer explicitly refuses to support 64-bit, the graphics tablet bluescreens win7 when plugged in, the others just do nothing). All work flawlessly out of the box on Ubuntu. Hooray for anecdotal evidence \o/