I also have this guy in slot 6.
When I DID have it in slot 2, it downgraded my GPU in slot 3 to X8 performance. Slot 4 shares the same resources as the M.2 slot so If I put it their it will downgrade it's performance. I'm not concerned with it being in slot 6 because the Intel 750 only runs at X4. Now the performance. My issues with riser cards are that they would get in the way of the waterblock for my GPU's. I have tried using risers. I have enough spare parts in my office closet to build 1 or 2 more PC's if I wanted to. My kids all have their own laptops, and iPhone 6's. My wife has her own office with a desktop, as well as a laptop, ipad air 2, and iphone 6.
When I was working on this project, I was using my living room's HTPC which I moved into my office. It is running an older core i7 CPU. Nobody in my house missed it. My kids and family are all spoiled when it comes to technology. They all have their own Samsung flat screens, DirecTV DVR receivers, and Amazon FireTV boxes. My son has 4 different game systems attached to his 55 inch TV in his game room. My 16yo daughter never uses the game room because she is has her own home theatre setup in her bedroom. Every online component in my house is connected to a shared drive on my router which has a huge music and picture library. My internet is TWC 300 Mbps so we don't really have bandwidth issues. My office PC has a LAN connection which usually gets around 330-350Mbps. My wife has her own business line for her office. All our laptops and connected streaming devices are on the 5Ghz channel and I typically get around 130-150Mhz connections over wifi. That's in my master bedroom which is downstairs. My router is upstairs. Our house is fairly big 2700 square feet.