The Efest 550mAh cell had a good run. I think it has been around since 2011, and performed very well in tests done by HKJ and dampfakkus.de. Those two testers have not yet tested the 700mAh version, but according to a user test here on BLF, it does not look very promising.
Review - Efest 16340 IMR Test
Probably the best IMR16340 still available is the AW 550mAh. But who knows, maybe Windyfire will surprise us with a top performing 16340, like they did with their 600mAh 14500 battery.