I started vapeing on a Riva 3.7 v and used it for 4 months. Then I got a 5v passthrough and used it with the Riva for another few months. (passthrough was for sitting at my desk and Riva was for going out) then I got a 5v box
mod and hardly touched the Riva anymore.
Now I'm waiting on my Lavatube which will be used as my main PV and the 5v
mod for backup. The 5v box mod is a little stronger than my passthrough so I mostly use that.. I believe the passthrough is perhaps 4.8 volts. ( I don't have a meter to check it)
Look at this wattage chart.
http://img41.imageshack.us/img41/8248/wattagebig.jpg
Even a .1 (point one) difference in voltage can make a big enough difference in watts and effects how your atty hits at a given ohm rating.
I like a solid 5v with 3.0 ohm atty's/CE2's. This gives me 8.33 watts. Now there are many ways to get that 8 watt range. You can get it at 4 volts with a 2.0 ohm atty on a 3.7 volt battery ( they top off when charged at 4.2 volts). People say that 8 watts is the sweet spot for vaping but it goes deeper than that. The 8 watts with a 3.7 volt and 2.0 atty will give you a different hit than getting 8 watts from a 5v and 3.0 ohm combo. The vape is warmer slightly, it produces lots more vaper and I find the nicotine gets stronger.
As much of a difference there was going from 3.7v to 5v, I'm willing to bet there will be that much more difference going from 5v to a higher voltage, and i want to experience that. This can only mean even more vapor production, and stronger nicotine.
Ask Creniker why he likes vaping at 8 volts. I bet he'll tell you he gets good strong hits, tons of vapor and doesn't have to suck on his PV till the cows come home to get that. It gets even closer to simulating the things we enjoyed as smokers.