Injora/ Amazon Axles

[Jbrick]

Hello all I'm sure this has been discussed before. I was hoping to get some feedback on what people think of the injora/amazon straight and portal axles.
Thanks in advanced

 

[CamoColton]

I haven't owned any, but in my circle of friends I've seen them grenade portal gears. Which I don't believe there is a "standard" that you could swap in like the ring and pinion.