I used the stock seat for a couple of years. It broke in at around 700 miles and was comfortable with the backrest on long runs. I would routinely do 3-4 hundred mile "day rides" about 600 per day on a trip before I stopped and a couple of 1000/24 runs for the challenge.
I wanted the Mustang seat for the looks and the fact that it was lower seating position. I bought the deluxe and for looks it is beautiful. The lower seating position helps me in backing the bike up and gives a bit of confidence in the corners.
Right now I am not impressed with the overall comfort compared to my stock seat.I miss the backrest and it burns my butt/upper thigh area after about 200 miles. I haven't had it long enough to compare with the break-in on the stocker so I am withholding comfort judgement for a bit.