I waited A Long time! for these. The 510 looks of good quality

The resistance reads the same as my Evolv 510
mods 
The threading is very smooth! The battery door is going to be the weak link on these, kind of expected that

Just have to be carful with the door when removing
batteries. They are metal of some sort? They are a little on the heavy side, maybe even a bit more than my 4s lipo 250c's, but the lipo mods are plastic (3D Printed)
All in All for $136! these seem pretty good
FT will still sell you these for the better price! I just put in a ticket & they invoiced me for the second one after the price hike. So I didn't pay full price & wait for a refund! Just paid the $136 invoice direct to FT
I'm curious to see how the dual 21700's will stack up against the 4S 1300mAH lipo mods?
I'm hoping for at least comparable battery life? I'l know for sure when I go back to work