Jimi....on the VMAX you really want a 2.8Ω or higher carto. I use 3.0Ω cartos ONLY, they all start out at 2.8Ω but end up at 3.0Ω after 4-6 hours of vaping. At that voltage I keep the VMAX from 3.2- 3.6 volts and have tons of flavor, not 1 bit of burning, and enough vapor to give you a nice thick vapor throat hit, which is the ONLY kind of TH I like, need or want. Let me know how those 4Ω singles work out for you. Another carto Im starting to warm up to, believe it or not, by Fuzzi's account is the DC 2.0Ω at 4.0 volts. Not the flavor the Fusions put out but not too bad at all.
Ya, if you get a good DC it can be a very nice vape on the Vmax. Problem for me was I managed to see 3 good ones out of 10 from Smoktech. You name every possible problem a carto can exhibit, I experienced it with the other 7. Terribly inconsistent. I have another 5 pack of the 2.5 DC's just sitting here, waiting until I feel adventurous again.