First, full disclosure: I worked at AndyMark during the run-up to the 57 Sport’s launch. (I was gone by the time it went live, though.)
The VersaPlanetary is hardly a wrong answer, with lots of options and nice things going for them. I’ve used them with success in the past on 4901, as well as BaneBots P60 (both for 5402 and my AndyMark Fight Night robot the last two years) and 57 Sport gearboxes (1293 used three last year, plus one CIM Sport on an Ri3D robot). But they do have some things that will wreck 'em, particularly exceeding the load ratings, impact damage (I notice 6911’s are pretty far out), or poor alignment during assembly. (And, of course, lack of grease…but you said you had that.)
While your mention of the DeCIMate gives a few hints, what motors were you trying to use in them? At what ratios?
At our first regional, the intake gearboxes were very far out, and did in fact also take some abuse by us trying to play defense with our arm :]. We used new ones during Semifinals and the sungear stripped during the second match, and we know from the video that there were no impacts. At the second regional, the intake gearboxes were much father back, out of the way from any impacts. Sun gears still stripped. The elevator gearbox was also stripped, but still worked. We only took those apart when we got to worlds and realized it was shot and we were just lucky it never siezed. When using the versaplanetaries, we used 1 775Pro on each, and 2 775Pro’s with a versaplanetary dual output adapter.
Once we switched to the 57 Sports, we used 1 AM 775 for each side of the intake, and 2 for the elevator, mounted on a DeCIMate. At worlds we abused our robot like there was no tomorrow (even driving over a robot while playing defense) and rammed the intake into just about everything and nothing happened to them.
After all the bad experiances with them, team 6911 will not be using the versaplanetaries for some time, and will use 57 sports as well as external reductions to reach the modularity of the versaplanetary. I was opened to trying the versaplantaries during the offseason this year, but one of the advisors is not up for the frustration they gave us.