Fit is not the best. Mine has a nice little gap between the tank and seat. It will also raise the seat height by about an inch. I'm 5'10", 31" inseam and tippy-toe with the gel. Not unmanageble, but trying to walk the bike while on is pretty much out for me.
The seat seems stiffer than the stock, but in the long run, this is actually better. It provides more support over a wider area than the stock which compresses a lot and causes pressure points. It takes getting use to, but it is an improvement in long distance comfort over the stock seat.
Given you're 5'9", I would suggest maybe a custom seat that allows you to get a good footing...