Some loss of power and increase in frequency/length of regens was expected, so there was few surprises (or regrets) after the fix. I can pour money into both cars for quite some time before the payout cash is depleted.
Had my wife not known the fix had been done to her car, I'm not even sure she would've noticed any difference at all (she drives faster than me, too). Her main complaint from the start has to do with the inconvenience of a regen that begins just before arriving home, especially since I told her to never interrupt a regen.
After the fix, the frequency of hydrolocking each winter increased to the point that something had to be done. Easily fixed it on my own, shouldn't be a problem again.
IMO, the pros of buying an unfixed, tuned car far outweigh the cons. StevenT knocked this one out of the park.