I assume you are wanting to know about Boge cartomizers. These are what I use primarily:
For my 5V PV, I use 3.0-3.4 ohm cartos.
For my eGo, regular 510 batts (both ~3.2V under load), or my 3.7V box
mod, I use 2.4 ohm cartos. Higher than that is too weak for me (although some love 3.0 ohm cartos on true 3.7V). Lower resistance than this is a bit too hot for me, even though the resistance is about the same as a regular 510 atty, they are a stronger
vape to me. Unfortunately I am only seeing Boge LR cartos sold in the 1.8-2.2 ohm range. May well be perfect for some, but that is too low for regular batts. You don't want to go lower than about 2.2 ohms on a regular 3.2V-under-load 510 batt, as it will drain the batt too fast and could damage it. They are fine for larger batts of ~450 mAh or more, but the small original ones really take a beating from LR
coils. That doesn't stop some from doing it, but this is the general word of caution for that combo.