I'm glad you posted this thread. I was actually logging on to post a near identical one. I'm also torn about the "free" upgrade to Windows 10. It's free now, but its unknown what the impact will have on gaming. If you wait until later, it won't be free, and will cost to upgrade. It's a conundrum. Windows 7 is everything I need; no complaints.
They say, "If it ain't broke, don't fix it". They also say every other version of Windows has had significant issues. Win8, Vista, WinME, Win95. Some people are saying Win8.1 is the version after Win8... I don't buy that. I think Windows 9 -err- 10 is going to have problems! (Win98 was better than Win95; WinXP was better than WinME; Win7 was better than Vista... I think the version AFTER Win10 will be better than Win 10. Just a hunch :)
One thing to keep in mind is that Windows 10 will not have or support Windows Media Center (WMC). On our home theater PC, WMC is essential, as it records all our TV shows. I believe Microsoft wants you to buy their XBox Live and use it for your media consumption.