I've tried several options to get a decent lower seat on my 1150GS, being a stumpy legged beast.
First try - BMW low comfort seat - plank like, not comfortable at all, 1" lower, which was good. Sold on to someone with a more padded arse.
Second try - Wunderlich low seat - worse than above, plank with lumps. Sent to Melvyn in Coventry for gel pads, came back with bit of string across front and seat pan (original BMW one) bent. In trying to straighten it out, I tore the vinly cover. Got it recovered and then sold it on.
Third try - Corbin seat, very comfy indeed, low enough, but so wide at the front that it made the problem of getting a foot down worse not better.
Fourth try - Sargent low seat, not cheap, but still on the bike a couple of years later.