I use 3 ohm cartos @ 4.4 - 4.8 v on my provari. Perfectly happy. I think alot of people do weird stuff like that because they come from egos and use 1.3-1.5 ohm cartos on it to make it work worth a crap. So they move up and stick with what worked and haven't used proper equipment on the new device IMO.
I am willing to bet a box of cartos to anyone who has a LT to buy a box of 3-4 ohm standard boge cartos pop it on the LT and crank up to 5 volts if they aren't happy as they were on ST 1.5 on an ego.