Personally, I use the same rules for mechs and regulated mods. If I'm going over the 80 - 85W range, I use 30A batteries. Regulated mods are supposed to protect you from mishaps, but I just don't trust a cheap Chinese circuit board to keep me safe. I use Sony VTC4's in mechs and in my iPV4 and they are great batteries. I have a couple of sets of the LG HG2's, and they are also great batteries, but I only use them in parallel devices over 80W. Once you crank up the wattage that high, the difference in mAh will only give you maybe an extra half hour of run time, and to me it's not worth the risk.