Honestly, high end Skylake simply isn't worth the higher cost over X99. If you're looking for performance improvements from your current setup, X99 seems a reasonable choice, particularly given that Skylake is the tick. The tock isn't going to be that much better in brutal seriousness, so you'd be waiting another 24 months for another architecture to come along before upgrading to anything besides X99 becomes worthwhile.
With Intel's current (utterly moronic) pricing of the 6700K vs X99, highend Skylake is totally irrelevant. Unless you're on Sandybridge and buying the 6600K, I don't see any reason why anybody would choose that platform. Not until Intel readjusts pricing.
I mentioned elsewhere, I got my 4790 for less than £200. Intel is charging £320 (a full £40-50 more than a 5820K, it's equal) for the 6700K. God knows what fool is in charge of product pricing stacks.