Sure. I thoroughly look forward to you trying out Ubuntu 12.04 and Windows 8 and seeing how they compare.
I think you will find that both are orders of magnitude worse than OSX. Why ? Because from a UI perspective both are complete rewrites and are reminiscent of 10.0 beta. Lot of potential but a lot of polish required as well.
I know and use both Ubuntu and Windows regularly. At the moment, OSX is still my operating system of choice mainly because the hardware is seriously great. The OS itself is becoming more and more awkward to me.
The funny thing is for people switching from other platform, rewrites are not a big concern because they're learning everything from scratch and some of the new stuff actually makes sense. For people upgrading, things being switched and moved is extremely annoying, at least at first.
I think you will find that both are orders of magnitude worse than OSX. Why ? Because from a UI perspective both are complete rewrites and are reminiscent of 10.0 beta. Lot of potential but a lot of polish required as well.