This amp has been rock solid! I had one issue with a speaker and had to replace it and went ahead and swapped them both out with Eminence D's just to have a matched set.
(I like uniformity

) Sounds Great!!!
As for any difference between the older vs newer .... I rehearse from time to time in a studio with all gear provided and they have a newer (Post Fender Aquistion) Redhead and a Hartke 1-12 kickback.
I can't get a good sound out of the newer one no matter what I do. It's so dry and barky. I always wind up using the Hartke. And ..... this is after running my USA Lakland Bob Glaub P/J bass with Aguilar preamp into it!!!!! Go figure .....
I have to admit I am surprised in the difference and would have never expected that but hey .... sometimes I guess that happens when companies trade hands .... who knows.
I can't say this is across the board but it certainly has been my experience in this event.
Anyway .... that is my 2 cents on the situation and thanks for asking!