On my 5v devices, LR end fittings either blow quickly or produce way too hot a vape. They probably wouldn't last long although I have never experimented, the vape is not pleasant.
In general you would probably want 2 ohms or more on 5v, and 2.5 ohms or higher would be sensible. Cartos produce a dead flavor compared to attys so some people probably use lower res to get more flavor. There are a lot of people who will tell you that 2.5 - 3 ohms is about right on 5v.
It depends on how hot you like it, if you can afford to replace the atty/carto more often, and if the flavors you like get burnt out at over 10 watts on the atty or carto you are using.
The best gear to run low-res atties on - IMO - is a big-battery 3.7v mod. A fresh batt gives you 4 to 4.2 volts, and that's about right for me with an LR atty. With an 18650 cell there is very little voltage drop compared to a 14500 cell. Everyone is different though. Cartos generally need more of a kick.
Below is a Black Bullet with an LR dripper rig. There are 4 parts to the top end - a 510-to-510 long extension, a drip catcher sleeve, a driptip, and an LR atty with 2 SS bonuts inside. You can drip 6 or 7 drops and get about 20 minutes' use or the equivalent of about 2 cigarettes. It is a good use of an LR atty.
