I plugged mine in, let it sit for a few, and took 5 large DL hits off mine at 35W on a coil reading 0.96 ohm, (so 5.8V), and the mod is maybe a few degrees above room temperature, about what you'd expect just from being held in your hand. The tank got warmer than anything else, but nowhere near hot.
The other problem I've heard people mention with Picos is the "weak battery" msg popping up when firing with the battery meter reading <50%, requiring a second press to actually fire the mod. I've taken my batt down to ~20%, and never had that happen. So, I dunno. I'll try it at higher power settings and check the voltage reading next time.