I know exactly the dim flickering you're talking about - my old hot backend caused the LEDs to do the same thing. You can almost see whenever the heater is running because that's when the lights flicker.
I am getting a longer battery life. And for science sake I took a massive rip through glass at 5 and can confirm I am getting a MUCH milkier hit than before.
On an unrelated note, they also shipped a replacement mouthpiece because I had issues with the screen coming out. Two days before the replacement arrived the threads stripped loose on my original mouthpiece.
Luckily the replacement threads on perfectly, but let it be a lesson. KEEP THOSE THREADS CLEAN! If you feel any sort of "gritty" feeling, be careful, I personally plan on cleaning my mouthpiece weekly to avoid this. I wish they sold spare MP's so I don't have to wait for cleaning