I am also 5’9”
The stock seat didn’t seem to bad at first but on long rides it became pretty aggravating.
Eventually I bought a used Corbin from a board member, nice seat that definitely made it easier to reach the ground, but the seat was a little to firm so on long rides on rough roads I sometimes had to stop and take a short break, then everything would be fine for awhile, another issue was for some reason that seat was very slippery.
Friend had a Seat Concepts so we traded seats for one tank of gas, I was happy to get my Corbin back.
Then there was a barely used RDL seat for sale very reasonable so I bought it, it was very comfortable but taller and wider than any other seat I had tried, I used it for two years, then decided it was simply to tall and wide for me. Told Tenere Guy I was thinking about selling it and he said he would like to buy it, said he had a newer Corbin that wasn’t slippery so maybe we could trade ? So he rode 300 miles to my house to show me his Corbin and yes it’s definitely not slippery like my first Corbin was and it’s also not as hard, so we traded seats, 400 mile day is the most I’ve done with it so far and it seems to be working very well for me, much easier to reach the ground than with the RDL.