RioJazz - so it seems that even with the firmware updated, you can roll back to Mix Control 1.8 and the older official drivers, as long as you are certain all of the beta drivers have been uninstalled.  Is that correct or am I misunderstanding?

NO!  Do not assume that.  Let me try to me more clear:
 
When I first updated to the beta drivers (a version earlier than the newest one), there was no mention of firmware.  It was just a beta driver.  From that, I could roll back using Support's instructions, and did so, to 1.8.
 
Now, however, it appears from the minimal description that using the 1.92 driver ALSO upgrades firmware, which cannot be rolled back.
 
That's how I read it.  The instructions are far from clear.

Soundwise
Not at all. You can set the buffer from a special dialog, which is a lot more convenient.

Hmm, can you clarify where to find this special dialog?  All I got was a popup with a couple of inadequate options the last time I tried the beta drivers.  

Dave76

Soundwise
Not at all. You can set the buffer from a special dialog, which is a lot more convenient.

Hmm, can you clarify where to find this special dialog?  All I got was a popup with a couple of inadequate options the last time I tried the beta drivers.  

Interesting!  That button on prior versions just brought up Mix Control.  

Update.  For my initial click problem, Focusrite Support just advised me to first try NOT the firmware update, but just a newer driver.  I had been using a 2.5.x driver.  They sent me a link to a 3.2.1 beta driver.  They speculated I was hearing a change in sample rates.  Since I have heard that sound before, I tend to agree even though there is nothing on my system that should be trying to change the rate.
 
I have to say, so far, after installing just the driver, I'm not hearing the initial click.  I need to live with it awhile.
 
Once again, I have to compliment Focusrite on quick and thorough service.

riojazz - are you using the 1.9 Mix Control with those new drivers, or the 1.8 Mix Control?

I've been in contact with Focusrite Support and thought I would give an update.  They had me install the 1.9b10 version of Mix Control (which doesn't require a firmware update) and the 3.2.2 beta drivers.  After doing so, I couldn't get any files to play through Sonar.  Even projects with a single track would not play.  I would just get an audio dropout message before playback even started.  Earlier in the day I was working on a complicated mix with lots of plugins using the 1.8 Mix Control and the 2.5.1 drivers and it played back perfectly at 3 ms buffer.  I work at 24/96.
 
I also attempted to install Mix Control 1.9b12, but the firmware update failed.

aspenleaf
I've been in contact with Focusrite Support and thought I would give an update.  They had me install the 1.9b10 version of Mix Control (which doesn't require a firmware update) and the 3.2.2 beta drivers.  After doing so, I couldn't get any files to play through Sonar.  Even projects with a single track would not play.  I would just get an audio dropout message before playback even started.  Earlier in the day I was working on a complicated mix with lots of plugins using the 1.8 Mix Control and the 2.5.1 drivers and it played back perfectly at 3 ms buffer.  I work at 24/96.
 
I also attempted to install Mix Control 1.9b12, but the firmware update failed.

Hi, That's the driver and Mix Control versions I am running now. (1.9b10/3.2.2) I'm currently in touch with a tech sorta spanking them for not having released official Window 10 drivers yet. Lol. Seriously. I am bantering them to get on it and I am surprised at the level of their patience with me. The Focusrite tech asked me to run a TDL log so he can pass it a long to their development team. I'll keep ya posted. Hope you can get the driver issues sorted. I tried updating to 1.9b12 and it was an epic fail!! 1/2 a Saturday wasted! 

aspenleaf
riojazz - are you using the 1.9 Mix Control with those new drivers, or the 1.8 Mix Control?

No, I still have 1.8.128.0.
 
The bad news is, I just discovered I cannot open the MixControl mixer!  It says "No Hardware Connected".  Of course, it is connected, and the unit is working, presumably with my prior settings.  I tried reinstalling with no effect.  I am awaiting another answer from Support.
 
This is not good.