If you need the hyperthreading, then the 4790k is the best option, as the 6700k really isn't much faster and the only other big advantages Skylake offers are DDR4 RAM support and better support for high speed SSDs with faster M.2 and NVMe support. If what you do needs a lot more cores and threads eg. more than 4 cores and 8 threads, moving to the X99 platform an something like the 6 core/12 thread i7 6800k might be a more worthwhile option.