Here's the standard gel seat. Much heavier than stock, but a fairly similar shape. Better, but not a lot better.
I managed to get a really good deal on a used (barely) Sargent low seat number WS-569. I wanted the low as I had seen a lot of negative feedback from Bandit owners who felt the standard was too high. This low seat is the same height as the OEM seat in low position.
First impressions: much flatter and narrower in the front and cushier. Edges where they contact the inner thighs are rounded. Supports the sit bones well. Nice carbon fibre effect cover material. Bigger gap between seat and tank (no paint rubbing). One piece with a custom base with a cunning storage pocket in it (nice). Has a rubber cover on the rear edge for the accessory backrest. Very well made. On a one hour ride it felt good. OEM 3/10, Gel 5/10, Sargent low 7.5/10 (for my backside - your results may differ). Recommended.