My $400+ Michigan seat is broke on TT...not buying any more of those or parts to fix. So I am riding on rigid seat foam.It's probably better than nothing but the problem on a mower isn't posture. All the shock from bouncing on rough terrain transfers to your back. If all you need is a pillow it would have been solved long ago.
A suspension seat is going to be a lot more effective. Do any of the glowing reviews mention how much they love it for off roading?