As a longer-time NVDA and Firefox user, I can confirm, that there indeed are certain, quite annoying issues with the newest Firefox release, which slow our, so far routine operations down!
The most annoying of those appears by operating with combined-lists:
We move, jump to a combined list, and it does open the way it did before, but then all similarities end.
When we move down and up in the list, NVDA doesn't read the list-elements anymore at all, so we have no idea where, at which list-elements we currently are.
With the help of a sighted friend, we figured out a "cure", a partial solution for the issue, but as I said, it's just a partial one, and using combined-lists is still quite...uncomfortable, and much more time-consuming than before.
Namely, whenever we enter a combined-list, we must press space, so then, and only then, the elements of the list will be read while browsing it, but then, when we wish to select one of them, we must press space again, if we don't do so, tabbing to the next element will not work.
Then, after tabbing to the next element, (for example imagine a row of combined-lists, containing options, settings, alternatives), we must press space to activate the reading of the next list, for if we don't, we won't hear a single word again!
And we have to repeat this process by every single combined list we wish to access, each single time, in cases of settings, options, many times in a row...normally, we had no such unpleasent hold-up with the old Firefox, so this issue will surely piss not only me off, but all other regular Firefox and NVDA users!
Plus, there are some other, less-annoying, minor issues, which I won't even mention here, but the fact is, that even many sighted Firefox-users keep complaining about this new release, so hopefully the Mozilla team got bombarded by complaints by now, and will correct these issues in their next release, which, due the tons of complaints I guess, they will issue pretty soon!
Summarized, the new Firefox is a nightmare for NVDA users, it even seems to work slower than the old one, (despite my change from Windows 8.1 to 10 yesterday), it is much less screen-reader-friendly in general, and since sighted users have also several, more serious issues with it, we hope for a new update correcting all those, ASAP!