Someone mentioned that all you do is order the seat, give a down payment of 100. and then Seth sends the seat and you send the old seat back in the same box. But, I called Seth and I thought he said to send him the old seat first before he will start production. So I need some clarity on that, along with does the single seat change any ergonomics of handlebars and seat heights? I am thinking of ordering next couple of days if this seat doesn't make it necessary to farkle other things..Thanks for the great forum.