As I re-contracted with Zen to save a few quid I got the new Fritzbox 7530 too so decided to do a check of all three devices I now have on my ECI cabinet.
HG612:
ECI:
Fritzbox 7530 (double NAT as no bridge mode):
I think the difference in upload may be the Traffic Shaper having a different impact either because of the lack of using PPPoE in pfSense or maybe even something about how the NAT in the Fritzbox is functioning. It may even be that the Fritzbox is using a lower MTU which could be impacting how the results play out.
What I was impressed with however was the jitter seemed much more stable on the Fritzbox when testing on dslreports. pfSense still has jumps to triple digits but the Fritzbox kept it totally under control through the whole test despite the higher throughput. I didn't bother putting the dslreports tests on here as the upload speed result was garbage for some reason, so it could also be it was just misreporting all around.