Just got down with the vas on the most recent Z77 OC Formula since there have been so many sessions with cold on the memory. Yes it is a bit messy at first the peace of mind of a condensation free session is totally worth it I think.
For just cpu, no need to go that hard if you live in a dry climate, but if the board is going to be benched cold on cpu, gpu and memory and is a permanent bench board then I don't think there is anything wrong with the vas treatment.
Also I don't think you need Hondacity style vas treatment with an inch tall layer of goo covering everything, just a thin layer and then melt it with the heat gun so it goes everywhere in those hard to reach spots.