Give this a try: Turn the unit on at max, you will probably get green in a few minutes. That indicates that the heater has reached the setting. Now wait for the thermal mass to build up, in this test wait 20 minutes. Is the top section (above the screws) very hot to touch? If it is, dial back to 3. Be sure the ELB is loosely filled no more than a half. Then take your hit. If you're not getting a strong hit or the unit is not very hot at top, submit a support ticket. There have often been subtle factors that the VXL guys can identify and resolve w/o needing to send the unit in. Not saying your unit is OK (hope it is, of course), just that a lot of times service has turned out to be unnecessary.
As far as a comparison to the OG, many have found that to not really be all that helpful. Some of the OG's just ran hot. Also, the heat range on the EVO is wider than the OG. My EVO between 2-3 is close to my OG between 12-1. But my EVO also begins to produce whispy but tasty vapor at a low setting, closer to 9-10.
And re the nail, might be worth repeating that the beta testers have pretty consistently found that less is more, both in size of the dab and the temp. After the unit reaches thermal mass, 12 seems to work well for many and the concentrate goes farther -/too much not only wastes, it can get messy, too.
Good luck.