I heard that the pins ran into some patent infringement issue (with Mafell?). Someone here might be able to confirm this. That's partly why the pins on the XL flip, not retract. And old fences themselves are no longer made or available.
Yes, the pins are better than the paddles in two aspects as far as I know:
1. You can make a series of mortises by registering against the previous milled mortises with no marking
2. You can make louvres by registering the strips with the two pins at an angle.
I've never come across the old fence/pins, and was told that you couldn't do 4mm dominoes with it. Some filing could be needed. True? What I heard about this could be misinformation.
As for accuracy, as I showed in another thread with my test cuts, my paddles (at the factory settings) are as precise and accurate as they can be. Zero calibration needed. This is what I expect from a premium tool manufacturer like SawStop, Jessem, Veritas, etc. though I know some found their DF500 off upon receipt.
My DF500 is 6 or 7 years old...never banged or dropped (I've seen that happen!). All its settings are as good and reliable as they were on day 1.