I've looked at/used alot of the manufactured ones out there and they all seem to have flaws, so I decided to make my own.
This winter I really need to finish it up. Just got it mocked up, tried it out, made some changes then the busy season hit. Designed it in CAD with steel tubing and aircraft aluminum to be pretty light, (about 20-25 pounds) compact when collapsed, and SUPER stable. It's made so it's really quickly and easily collapsible and adjustable in height so you can use it standing for when there's brush/grass or sitting. You just have to use a stool or chair for sitting as I've found having a provision for sitting mounted directly on the table makes almost any lightweight portable bench too wobbly for really accurate shooting.
This thing can double as a super stable shooting bench for really fine work.