So you use the m50 below 30w most of the time? Your review and recommendation of the mod is not fair then. I know of at least 30 vapers who use more than 40-50w all day. To give a just and fair review, you would have had to state in the beginning that the mod is poorly acquitted as a 50w mod. But better below 30w. That's more thorough IMOIf you want a device that performs consistently above 30W then it would be best to go with any of the various dual battery devices out there such as the iStick 50W, Smok M80, Sigelei 100W, etc.
At high wattage (50W+) you will drain a single 18650 (2500mAh) fairly quickly.