Yeah, agreed. The differences I remember, being pushed on me, are:
Heated front seats
Power seats
Cloth seats and inferior interior materials
Power mirrors
Power steering wheel tilt/telescope
Carpet
Center console with USB. Rear USB.
Center console with covered storage.
Lower than low sound system (SR+ already not good)
Physically smaller battery
Lower performance
No live data for maps, no satellite maps, no streaming music, no web browser; though I've seen none of this in my SR+ anyway.
If the only differences are essentially the 92% battery charge of the SR+, which can then be charged to full, then the cars are the same. Absolutely worth downgrading.
Tesla would be so much better off offering a few upgrades to the SR+ owners, to make the car meaningfully different from the SR, rather than paying out a lot of money. Of course, if they don't then all SR+ owners should logically downgrade, unless they have an emotional reason not to.