Got my ProVari a few hours ago and, of course, I'm loving it!
The AGA does look better on the Vamo than on the ProVari, but I won't be getting the pro ring. Too costly for mere aesthetics, IMHO.
I do use my Vamo in 18650 and it might help, but it is still top-heavy. I knocked my first one over so many times that I destroyed it.
(Well, elbowed it off the counter onto tile and off the workbench onto concrete.) It had loose - or kind of wobbly - 510 threads from the get-go, but my replacement has good, solid threads. Both Vamos are SS.
I started the ProVari in 18650 with the AGA and I don't think it's all that more stable than the SS Vamo. I think it might be a bit better in 18350 mode, though. These are my first 350 batteries, so I haven't had much time to get acquainted with them yet.
With my record for dropping these mods, I am just about to pull the trigger on the Tatroe Base I've been reading about
here. The thread is about the mini, but they've stated that it works with the standard, too.
That base should make feel better even though if won't prevent elbow launches.