Yes, the firmware that was installed was version 4. The firmware updating procedure provides a clear message about which version the aids have and which version they will be updated to. Mine went from version 2 to version 4.
So far I would have to say that streaming has improved. I use my iPhone to stream podcasts and music while I am walking and it seems to work better. With version 2 I would sometimes get a “ping pong” effect where the sound would bounce back and forth between my two aids - this would last for a minute or two before fading away. I also experienced an occasional reboot from one or the other aid and so far since the update that has not happened. It is a bit early yet to say if this problem is cured but so far so good.