Was happy with my Selle SMP TRK until my rides got over 50 miles. I switched to a Rivet Imogene saddle about 2 months ago after hearing some positive reviews on bike touring sites. My Imogene was as comfortable out of the box as my Selle SMP and is keep getting better. Completed a century ride and sever 60-80 mile rides. Never once thought about the saddle on my rear end on these rides. I'm 6' and 265lbs.
Rivet will let you try out a saddle(s) for a few weeks for about $25/saddle. They even have a 364 day return policy. Give them a try if your looking at leather saddles