RIght, seeing as nobody else seems to want to chime in:
What games are you going to play?
What other hardware is this all getting matched up with? (Particular interest is storage, monitor, graphics card)
Right now, the standard recommendation for somebody looking to spend good money on a gaming CPU/GPU/Memory combo would be something like:
i5-6600k ~ £210
H110 or Z170 motherboard - ~£60 or £100 (happy with base clocks or wanting to overclock)
16gb of DDR4 memory in 2 sticks - ~£100
With a note that you could go down to an i5-6400 without seeing too much loss of performance, especially if not interested in overclocking.
If someone has a particular interest in virtualization, or tasks that are rewarded by Hyperthreading, or are just willing to push the boat out in terms of money for very small gains, then there are i7 processors that go into the same motherboards for £280-£300. The cautious note is that that extra £100 would almost certainly have more gaming reward if put towards a graphics card. It would probably have even more reward put towards saving for a new £200-£300 graphics card in 18-24 months time.
However, your previous purchase of a ludicrously priced processor and reaching straight for the high end items here suggests that money is not really restricted for you here.
Unless you already have a GTX980ti or better graphics card, then its worth noting that buying a new graphics card will do more for gaming performance than spending any amount of extra money on processor and putting in your old card. (Except for the likes of DORF FORTESS). So bear that in mind. Edit: Just seen you already have a 295x2. I mean, a 1080 or Titan X is a bit better, but may not apply to you.
Even given the lack of money restrictions, the most sensible option is probably still to just get an i7-6700k / Z170 motherboard and as much memory as you can stuff in.
If you still want to spend more, than yes, the socket 2011-v3 solutions are an option. These have real benefits, yes - but they are benefits that most users won’t even see. The processors don’t run any faster than those in Socket 1151. So, what do they offer:
More CPU cores. Rather than the quad core of the 1151, you get between 6 and 10 cores on the 2011-v3 chips. However, most games care much more about per-core performance than number of cores. And with almost all gamers running quad core machines, don’t expect to see anyone worrying about making their games use those cores either. Could be useful if you do a lot of heavy-lifting photography, videography or encoding work though. More cores also means more heat to get rid of and more power to drink, too.
More memory bandwidth - fancy quad-channel memory setups letting data go between the memory and the CPU faster. In theory, sounds like it should score a big win, in practice, brings relatively few benefits for most real-world tasks (including gaming)
[*]More PCI Express lanes- So, PCI express is how all your add-in cards (like graphics cards) communicate with everything else. The more lanes they have, the more data they can send back and forth. The long slots (the type that your graphics card can go in to) offer up to 16. On a 1151 socket CPU, that’s limited to 16 - so only one card can get the full whack. If you wanted to run 2 cards in SLI/crossfire, they’d have to split it down to 8 lanes each. And if you wanted to add a PCIe SSD (even faster than an SSD in SATA3), then that needs lanes too. On the other hand, if you’re happy with just one fast graphics card (much less fussing around to make it work), and a SATA3 SSD (still fast enough to start windows in ~30 seconds and keep loading times pretty low), then you’d never even notice the difference.
So yeah, the question as to what it makes sense to get really depends on how much you want to push the envelope in terms of setup, and how much you’re really willing to spend.