I'm kind of in the same boat as the OP sticking pretty much with the 510 but interested in a mod, but I'm pretty close to a decision: Going with the Xhaler. The Chuck is quite interesting with its customization, and the 905 (Which is a Chinese Screwdriver knockoff) for $57 at Nhaler.com is an absolute steal, but the Xhaler with a 510 adaptor and 5V seems like the "sweet spot" as far as I'm concerned.
An important point that seems to be missed by many is variable voltage. A lot of mods just use one 3.7v battery which means that the only difference between that and a regular PV is the mAH rating of the battery (less time between charges). For me, I'm okay with my recharge cycle (I carry at least 2 batteries and a PCC and I'm good all day) so the only advantage a mod like that would give is a little more consistency...but after tasting Drew's HV juices and hearing that running at higher voltages (with 5v being considered the "sweet spot" by most reviews I've seen) produces even more vapor with stronger flavor--THAT is an upgrade that is worth having as far as I can tell.
My cart is loaded and ready to check out, Santa. *hint* *hint*
An important point that seems to be missed by many is variable voltage. A lot of mods just use one 3.7v battery which means that the only difference between that and a regular PV is the mAH rating of the battery (less time between charges). For me, I'm okay with my recharge cycle (I carry at least 2 batteries and a PCC and I'm good all day) so the only advantage a mod like that would give is a little more consistency...but after tasting Drew's HV juices and hearing that running at higher voltages (with 5v being considered the "sweet spot" by most reviews I've seen) produces even more vapor with stronger flavor--THAT is an upgrade that is worth having as far as I can tell.
My cart is loaded and ready to check out, Santa. *hint* *hint*