So I decided to invest in this breakthrough system that brings El-Cheapo Lighting SolutionsTM to a whole new level 
Warning: if you want or need TTL or any other automated function you can stop reading now, these babies are all manual.
So what makes these speedlights so special? Price for one ($300 for a pair, including the radio trigger and a pair or receivers that mount on the side of the unit)
But the main thing is that it's the world's first speedlight to be powered by a rechargeable Lithium- Ion battery. And it's a massive one too, here it is next to my camera battery for context:
It's supposed to have the same capacity as 12 AAs, in practice this means that the flashgun performs about the same as with a battery pack - but without the battery pack.
Or even better in some ways, this video shows recycle times compared to Canon's flagship:
Specs say 650 full-power flashes per charge, I didnt have a chance (or inclination ) to confirm, but from my messing around this afternoon it looks possible.
The other nice thing about Li-Ion is that it has no slow-down towards the end of the charge, it has a uniform performance until it shuts down, and it also gives a much more accurate reading of remaining charge than AAs.
So just when I was about to kiss my eneloops goodbye, I realised I still need a couple for the FT16 radio trigger. The trigger/receivers seem reliable from first testing, but I particularly liked the fact that you can remotely control the power on each flash individually, or both at once.
Basically you "name" each unit from the rotating dial on the receiver, then pick a "name" from the dial on the trigger and you can change the power with the +/- buttons in 1/3 stop increments. If you give the same name to both units, you control them both at once. Simple and effective.
Range is not of huge interest to me, but out of interest, 40-50m (line of sight) was the longest I could go before losing one or both flashes.
Thats a bit average performance these days but good enough for me.
The system is also supposed to be capable of wireless High Sync Speed, but for that it requires a different set of triggers, again by Godox, called Cells IIc. I got a pair of them too but never managed to get them to work on my fujis for some reason. They are the Canon version with the 5 pins, I tried covering 4 of them with a piece of film but no luck.
The FT16 however syncs up to 1/1000 on my X100S, and again that's good enough for me.
I might experiment with other triggers later though. The good thing about the FT16 receivers is that they mount on the side of the speedlight, so I can always use another transmitter on the camera and receiver on the speedlight foot, and still use the FT16 just for controlling power maybe on a lanyard around my neck.
Overall, happy with the purchase, and to be honest a little suprised with the quality, considering what I paid. These speedlights are heavy and very well made, they mount securely on the camera hotshoe (which is more than I can say about fuji's rebadged sunpack), have a big and clear LCD, nice big buttons and generally feel like it can take a beating and soldier on.
A couple of things I didnt like is that the protective cases are too snug and dont fit the speedlight with receiver on, and the receiver itself feels flimsy and doesnt seem to mount on the flash very well or easily. But these receivers are cheap as chips, if I break something I'll just order a couple more for spares.
Just for disclosure, I'm not in any way affiliated with Godox or their distributors, just happy I found a speedlight I like and works well with my Fujis and I thought I'd share