I've used the Cobra manual, Cobra electric, Udo Rumpf with and without lateral adjustment, Steve Koerner with and without lateral adjustment, an old style Mark Mocho rigger, and a couple of home made ones.
Will use an IMI electric in a week.
Not a fan of the gas strut versions of any of them. Thought the one Udo made for my 26E was the best.
The training wheels that you spin out of the way can be a problem, but so can the tricycle gear if the glider has a lot of dihedral.
ASW20 will be easy to rig. Anything with spar end spiggots (mostly old but plenty are still made, like New Ventus and JS3) are more difficult.
With any rigger, get flat free wheels or make the wheels flat free. Some older Koerner ones had low capacity wheels that fail, believe MM has fixed that.
Jim


On Tuesday, December 5, 2017 at 7:22:41 AM UTC-8, wrote:
Steve invented the 3 wheeler which won't flip over in most cases. With a 2 wheeler, a problem arises during disassembly when wing is lifted off the tool to shove it into the trailer............the out-rigger wheels are retracted and you must remember to extend them or the stand will fall over as you lift the wing, prior to shoving it into the trailer. If the tool falls over it will most likely strike your fuselage! Ask me how I know this to be true!

The 3 wheeler with lateral adjustment does have a hidden flaw. Steve's original design didn't have lateral adjustment and the vertical post was welded in a stable location. The lateral modification alllowes the vertical post to move well past the "stable" location of the original design. If the operator forgets to lock the lateral adjustment, a slight wind can/will allow the rig to move all the way to the "unstable" end position and the wing and tool can flip over.........ask me how I know this?
All in all, I believe the 3 wheeler to be the better design, but both models demand your un-divided attention!
Hope this helps,
JJ