My above comment aside, I have a Corbin seat and I love it, however since the factory is only a couple hours for me I took advantage of the ride in service and made sure the seat was perfect before I left. It took all day I got there at eight in the morning and I didn't leave until after five in the afternoon and I had to send the seat back several times letting them know that I expected it to be perfect.
Even with all that, a couple weeks after I bought it I pulled it back off the bike and noticed that the four bolts holding the mounting brackets on had only been put on hand tight by the Corbin technician, I re installed them with blue Loctite and haven't had any issues since.