Thanks for that Tellboy - suddenly I understand how the vibrola works, sounds good to me :D
So, as long as it's installed ok so that it "returns" to the same place consistently, it's all the standard stuff for tuning stability - strings installed well on the tuners, nut slots attended to, and so on.
The only new issues for me would be strings over the T-O-M bridge. The jury seems to be undecided (on the old interweb) as to whether roller saddles are a must-have or not. At the moment I'm leaning towards well-maintained and lubricated standard saddles (mine are always lubricated with 3-in-1 anyway as a vague string-protection against me and my acid sweat).
How soon I do it depends on our good friends at Vibramate - they're working on a short-maestro version of the no-drill solution they've already done for Bigsby trems. I understand the Vibramate plate raises the trem higher off the body than usual, but that this actually appears to be a good thing to users who've installed it and who also have experience of body mounted Bigsbys.
No release date yet, but I'm guessing weeks/months rather than years. So I'm going to go for the no drill option first to see if I have a use for a vibrola before digging holes in my geetar...