I couldn’t bring myself to spend a chunk of money on a fancy dan seatpost, but got round the issue by buying a new bike with one fitted.
They really are rather good. I always used to stop and lower or lift my seat for certain bits of trail, which I didn’t mind doing, but on unknown trails it was best to compromise and have it somewhere in the middle and leave it. Less stopping, sure, but ups were harder and downs were more awkward. Not any more. 😀
My other bike requires an allen key to alter the seat height so i’ve the best/worst of both worlds.