Never used Tuff Kote, but I'm a huge fan of Resolene on my guitar straps. Seals nicely, wears well, and keeps the dye where it's supposed to be.
Various lacquer products work well, also. Clear Lac and Wyo Shene are the same as the old Neat Lac that a lot of people used to use. I plan on using on some of my things soon.
Don't know if you are familiar with Freddie Matara, but I've seen him mention that he uses RTC Leather Finsh, and gets excellent results.