Hi Sik. The defining factor is the device atop the battery. A vivi nova atop a mechanical mod will be just like the vivi atop the twist @3.7v....
The reason for mechanical mods is to only be limited by the amperage output of the battery itself. Ie being able to run a rebuildable atomizer say at .7ohms......... Jump over to the rebuildabl atomizer threads and take a look..... there are some stunning devices, being run by mechanical mods.....
and if you want to change the voltage of your setup you could look in ti getting a telescoping mod that you could change your battery setup from 3.7 to 6v the 6v set up will give you a hard hit on most anything you put on it
I really like the Bolt. Sure it's a cheapo device, but it's nice, saves money, and lets you try out mechanical mods and see if they're for you!
Ended up with an eGo-T v2 and a 3.5 vivi nova 1.8 also have some 2.4's also.thanks for all the advice. definatly going to try an rba soon.