I just picked up a PD270 and wisely before I peeled off the shrink wrap I read 4 reviews including one by Nick at GrimGreen. Every one of the reviews rated this mod poorly. The 510 connector being crooked,and your tank sits tilted, too shallow of a 510 male to read some devices. Poor resistance reading and not stable. Apparently ok in watt mode, those that use temp it;s poor. I immediately took it back and picked up a Fuchai 213 plus which has quite good reviews.
The 20700 batteries were interesting on the 270 but may be cost prohibitive, luckily there is a sleeve adapter for 18650's.
Cheers
Les