I know. But I'm not offering opinions. Just facts, Ma'am.
Ego batteries have a working voltage of 3.1-3.3v (there is some discrepancy between different testers and different batteries), but I'm confident that no stock eGo is capable of delivering more than 3.3v under load (not unloaded). Scottbee has been testing them for ever and his findings stand.
http://www.e-cigarette-forum.com/forum/joye-510/65055-battery-voltages-surprise.html#post962734
2.0-2.5Ω is generally considered to be moderate resistance and is widely recommended for the ~3.2v eGo/Tornado/Riva class batteries, even by the most cautious vendors, including Hoogie from Madvapes:
http://www.e-cigarette-forum.com/fo...1-etc-filler-type-cartos-398.html#post2901193
Per Scottbee, anything above 1.0Ω is theoretically safe for the eGos, but I wouldn't go below 1.5Ω. Just in case. I'm using eGo-t atomizers, regular (2.1Ω) and LR (1.7-1.8Ω), on my eGo without any ill effects.
There are new Rivas on the market, the SE Rivas, available at Liberty Flights, that actually deliver true 3.7v under load, but this a relatively new addition to the series and still rare.
VV means variable voltage. You can set is as low or as high as you wish, so there can not be a recommendation against or for using anything on a VV mod... per definition.