7 always has been, stable & reliable to begin with, irrespective of any particular security program. The OS is good, some securites, well, that's another story/issue.
Kurt, hate to admit it but, can't decide what 'uefi' means but, Windows 8 does not mean a need for ARM hardware. It works well 7 nicely on multiple platforms including, good ole, existing non-ARM, non-Touch PCs & laptops. But, certainly, there is no obligation to "rush" to it. Well, except, maybe that the $40 bargain doesn't last forever. And in some ways it's even better than 7 which, yes, is good.
Cheers,
Drew
Link Removed
'uefi demystified" replacement of bios: Demystifying UEFI, the long-overdue BIOS replacement | ExtremeTech
still wading through the details, uefi looks good: Link Removed