There were no changes or parameter resets for the Drive block. There were several parameters reset in the Amp block: bias, negative feedback, bias excursion times, Input EQ Low Cut, and several others.
If you had manually changed the Input EQ Low Cut to a higher value it would've been reset to default by the latest beta. That could possibly be what some people are experiencing.
In the end it doesn't matter what someone's OPINION of what sounds better is. All that matters is how the models compare to the reference amps and every firmware is an improvement in that regard. The latest beta solves several minor but nagging inaccuracies that have been bedeviling me for years.
FWIW, Rectos are big, flubby, messy sounding things. What you hear on recordings have been heavily eq'd to sit in the mix. Because Rectos are big, flubby, messy sounding things they respond well to subtractive EQ, which is the technique used by producers and engineers when mixing.