Ok, I caved and got the update. Why? Because after some thinking I came to a conclusion that:
1. It's unlikely Tesla will lower the price again. At first I thought they might, but then changed my mind. If this was just about making additional revenue, they would have lowered the X60 upgrade which they did not. They could have sold the 40->60 upgrade for $1000, or discount other options like 72A charging (also discontinued for 75's) to make extra money. This made me think the S60->S75 price reduction was mostly to smooth over the new S75 price reduction with people who purchased recently - a customer relation move.
2. This option does add to the car resale value more universally than other options like UHFS etc which are not universally sought after.
3. I will eventually do it when going on a 2 Tesla trip somewhere anyways so that our 2 cars have the same range (technically the 75D now has 6 more rated miles than the P85D), so might as well do it now and enjoy not having the nags earlier.
4. With a more limited "unicorn" status, the software limited S60 will probably not receive as much software testing for new software updates, so I can foresee some potential software bugs unique to software limited 60's. One interesting example, we've always had the charge limit set to 100% since new, ignored the nags (clicked no), but somehow the charge limit lowered itself few days ago to 50% after the car charged to 100%, so would not have been a problem the next day, but chances are my wife would not have noticed it for the following day - she needs more than 50% in a day to comfortably drive the kids around.
PS> Was going to change my poll vote for this thread, but still don't agree the price is a steal