After having hesitated quite a while, I finally upgraded from MC 6.01 to 8.4. today. Worked like a charm - apart from NewBlueTitler. Ver.1, that came with the Avid installer package, immediately caused a hard crash of MC, after having inserted it into the timeline. Following the advice in another thread, I downloaded Ver.2 - same outcome.
I'm running a certified system from an official reseller (HP Z820, Win7 pro 64Bit, 16GB Ram, 8 TB Drive Space Matrox MXO2 Mini, NVDIA Quatro 2000, Nvdia drivers, matrox drivers and QT upgraded to to the currently certified version, after uninstall and before clean install of MC 8.4). Really lucky, that I've still got Avid FX and Marquee at hand, nevertheless I'd like to use BlueTitler as well. Any suggestions?
P.S. Advice for those who're going to upgrade like me and using the Grimm Levelnorm Plugin. Mine (purchased End 2012) wouldn't install anymore on MC 8.4. A simple download of the current trial version fixed that problem. It automatically recognized my 'old' serial number and integrated flawlessly into MC. That's how imho 3rd party integration and upgrading should work.