If you're getting about a full day from a 18500 I may need to get new batteries.
I think that depends on the person vaping. I can't stand 2ohms on a mech mod - too weak. I sometimes use a 1.5ohm Cisco spec 306 on my mech. When I do, I find myself putting in a new battery when the current one reaches 3.8 or so volts . .so I don't get much battery life at all - even from an 18650.
With a 1.0-1.2 ohm coil, I tend to change batteries at around 3.6volts - so at least I get a few hours out of the battery.
When I'm at work, though, I use a VV device and a clearo with a 1.8ohm coil. This will perform well all day. Of course it wont peform at the same level as a 1.0 coil on a mech will - but it's quite acceptable.
So, for me, I have 2 totally different set-ups for different situations. When I'm out or at work and don't want to mess around with my e cig - I use an ego-twist and a mini nova with 1.8ohm head. The juice and battery last me a work day, easy. At home, I use my mech mods with my RBA's and swap batteries a lot.
I have several crappy mech mods and I want a better one. I'll stick with my twists for on-the-go vaping . . but when I'm relaxing at home I want to use something *nice*. Thinking of getting a Super-T Ela or a REO Grand or something like that. A nice mech won't make the battery perform any different, though . . but at least I won't be dealing with wonky fire buttons, cheap feeling threads, etc.
My smoktech telescope used to stand up and not fire under its own weight . .now it does and it's a total hazard if I ever set it down and forget to lock out the fire button. Already had one close call.