As the Director of IT for a clinic, I deployed 7 company-wide two years ago. Pretty much every new computer in the last year I've had to deal with comes with 8, but I use our deployment server to put 7 on them right away. 8 IS a little faster under the hood (they've stripped out a lot of legacy features to trim it down, and added a lot more threading and multicore support) but the interface is so unbelievably abysmal, I don't wish it on my worst enemy. The 8.1 update makes it only slightly more tolerable, but nothing is where it used to be or should be.
Like Cagey, I've been programming old-school computers since the early 80s (although I think he beats me by a few years with the Altair, my first machines were the Apple ][, Sinclair ZX81 and ZX82). And like Cagey, I run either Ubuntu or Linux Mint on my personal, non-work machines.
For most users though, I would either run 7, or wait for 9 to come out.