El Capitan, Nuance Voices

The down sampling of the voices is also gone. In the past, in order to get clear quality, you had to use Terminal to produce the output from the voices. When certain speech services used them, you'd notice a huge lack in clarity as opposed to when using say through Terminal.

This issue is finally gone after four years.

They still have not made these voices use pitch correctly, such as when you use upper case letters. As an example, it still says capital A instead of simply A while raising pitch. If you set it to speak capital, it will say Cap Capital A.

However, they are quite a bit faster, though I find that when you switch to other application they do tend to lock up for a little while. Giving them a few seconds to breathe seems to resolve it.

Well, the quick nav issue still is not fixed. I am noticing that if I use the shift key often, it tends to happen, so I think it may be part of the problem and cause certain keys to be held down. I originally noticed this when I would use a virtual machine and holding down shift often for certain tasks. Trying this without running the virtual machine also causes the issue with quick nav, but unfortunately it is not consistent.

For me, I can easily deal with these issues mentioned on the bug list. I can only reproduce two of the serious ones, all moderate bugs and five of the minor issues. The Audio ducking I can barely even reproduce, and I see it so rarely these days. It primarily seems to happen if VoiceOver reads just as an application sound plays, but I've never seen it happen with continuous playback such as iTunes.

I think the voices are better. Far more responsive and much snappier. I can deal with them locking up a few times, although it is a minor annoyance.

You might have a different experience than I do, but I've never found it to vary all that much between my macs. In a majority of cases, I can reproduce the same issues anywhere unless I am using a very specific configuration.