So I bought the upgrade, more for old times sake than need. I still love ACID and how it worked and what doors it opened for me. The new UI isn't all that new or good, it's at best a bad coat of paint. They seemed to have made little or no changes to how it all works. If it was awkward or bad in Pro 7.0, it's still awkward and bad in 8.
None of the new plugins seem to work outside of it (though I didn't even try the effects just the VSTis). There aren't really that many included plugins to be honest, they have a "rompler" and a set of sounds for it, based on Yellow Tools Independence. It's not very impressive. A weak synth and a slice player without a lot of features.
Video support is limited to AVI and WMV files.
The MIDI editor appears to be the same as it was (though my memory isn't that good on the details).
It seemed to have a lot of trouble scanning all my Native Instrument plugins. Had to kill the scanner a few times to get it to go through, but I was able to select each one in the Failed list and rescan it and get them added. I suspect the problem has to do with Visual C++ Runtimes and or shared libraries. Oddly enough their own plugins didn't make it through the scan and had to be rescaned. But again I suspect it's one or more of my other plugins that caused the problem. The sfvstserver app runs two processes, the first one uses less memory and starts another as the actual scanner. If that one hangs (it hanged for every NI plugin I have, which is a lot) you can kill it and it will continue on. Pretty much the same thing I saw with SF12 trial.
To get the instruments and loops you have to use a menu item under Help menu, "Download instruments and Loop Collections" The loops they include aren't very impressive compared to what Sonic Foundry/Sony used to ship. MAGIX isn't exactly artist friendly with their licensing either. I'm not even sure I can use any of the loops they include. They do send you a code to purchase one of five packages on their store, it appears the code works with buying the commercial unlimited use version, which I guess is something.
It doesn't really scale to my 4k monitor very well. But then most DAWs don't so I'm not sure I should give them that hard a time over it. Most of the dialogs and non-main screen are still using classic Windows UI. It's not really fully themed.
The upgrade should have been $49.99 at most. It is 64bit which I guess is something, but not much more than that. I'm hoping to find some other minor improvements but so far its all about the 64bit and the bad UI make over.