Hey there!
I wanted to let you know that my computer survived update from 8.0 to 8.1. The Presonus ASIO audio works without driver reinstall. My plugins count shows the same number of plugins. I have not started testing plugins, but 1 plugin failed. Guess what it is. That's wright, it is Session Drummer. I had problems opening it before update, after reading long thread about it, I installed something from Microsoft and it fixed the issue. Long enough to insert it in the track and create MIDI drum track. Should of freeze it- now SD is not opening.
 
I also lost Roland V-Synth GT connection to the computer. No MIDI or Audio. Actually computer feels when it connected and disconnected, but Sonar is not recognizing it. I have to check for Roland driver- it said they did not have it and will let us know if they make it, but I did see some Windows 8 drivers- I dont think it said specific 8.1...
 
Otherwise the update was uneventful. It really is not such a dramatic change, but computer acts like it was doing a lot of stuff on it's own. I will be testing other plugins and let you know what is missing. If you remember what it was that I installed for Session Drummer or saw the old thread, please, let me know. For now- check out exclusive Crystal method album preview. The release is next week but I got Pandora Preview as a fan club member. (This page should play The Crystal method new album). http://www.pandora.com/st...ay/1793285298583258341

With Session Drummer first thing to do is run windows update several times first (and reboot), before we need to look at something like the C++ libraries. Cheers... There was another thread somewhere about it recently... Thanks.

It seems that Pandora is unavailable to Canadians so the link won't work unless you are in the US, Aus or NZ.

Made the jump to 8.1 last week. Pretty painless. I did have to re-register my XLN instruments. Other than that all has been well. X3d even seems a little snappier since the jump from 8.0.

I'm using my backup system as my "recording system" is down for motherboard warranty repair work.  This backup system is Windows 8.1.  Everything installed without problems.  My Frontier Tranzport had to be installed in a Windows 7 compatibility mode, everything else in native mode. 
 
The backup system had Sonar X2 installed previously.  It now has X3.