Initial impressions of FSD 12.6.1 (coming from 12.5.4.2) on my HW3 Model Y: WOW!!!

- E2E highway is a game changer. It absolutely drives like a human now, changes lanes at the appropriate time, and early enough. Lane changes are happening immediately, and the car leaves the passing lane exactly the way I would do it (in standard profile at least). 

- it is SMOOTH! That controller improvement is mindblowing - no jitters, no awkward hesitations. Car feels like it knows what it's doing.

- Speed profiles just nail it, on city streets as well as on highway. Car goes with the flow!

- Deceleration (even in unplanned situations like stopping for an opposum crossing the road, see video) is smooth like butter!

- earlier lane change - yes! No longer waiting for the last possible second. I have one specific spot where 12.5.4 (and earlier versions) have always waited to the last chance (and often missed or had to squeeze in), now in that same spot, the car just changed into the correct lane at the earliest possible time. Awesome!

- one issue I observed (that seems to have been inherited from V13): at one light, the car seems to anticipate when red lights turn green and goes too early.

But man @Tesla_AI @aelluswamy @philduan - you guys did an awesome job with this version for HW3!!