Blech, screw the Kumho 712. It's not very sticky nor is it special in any particular category. I really am mystified as to how it has developed the reputation it has.

If you want a reasonably sticky tire that is not too expensive and has better tread life than the absolute stickiest tires out there, then the only tire you should be looking at is the Yokohama AVS ES100. It is way stickier than the Kumho 712 and lasts longer than the top eschelon (in terms of stickyness) tires.

If you want the absolute stickiest tire in both wet or dry conditions regardless of treadwear then there are several tires that are very closely comparable and mainly differ on price: Bridgestone Potenza S-03, Kumho Ecsta MX, Goodyear Eagle F1 GS-D3, Pirelli PZero Nero, Toyo Proxes T1-S and Michelin Pilot Sport are some examples. The Kumho MX is the cheapest option in this category and is actually a good tire unlike the 712.