I am in the same boat as the other two - I have only been on it for about a 100 miles, but the quality seems good. I sit more to the rear of the seat, away from the tank, so he made the drop a little lower for me to have a nice cushy section right where my butt goes. In other words, it fits like a glove and I no longer have the high heat concentration that I experienced before or the desire to jump of the seat after a half hour of riding. I am really looking forward to breaking this in a little more and see how much better it gets.
Pros:
Great mod for the price
Quick turnaround
Pleasant experience
No more underpants heat (so far - need to do a long ride to make certain)
Custom seat for your height, weight, and sitting position
Cons:
Not leather (could go either way, but I like the feel of leather)
Consolidated tips for those of you sending off:
Do not let UPS box it for you or you will pay for it (My shipping was 35 each way with discounts).
Do follow all of Spencer's requests - send in the picture, explain what you need, how you ride, etc.
Discuss the gel core insert he uses - I like it so far