Quote - Khory.. yeah.. big difference.  TBH.. when 4.5 first came out, I tried and installed it.  When I found out that it hosed Reality and all my other plugins I went back.  A format wasn't required.  My runtime was intact; so, I pretty much left it alone.  Going back to 4.0 wasn't a big issue.  I just hate programs that are like studio where it'll write over or uninstall your previous version.  It's totally not necessary.  Take photoshop for example. I have cs2, cs3 and cs5 all on my system at the same time and all three of them work fine.  Like others in this thread, I'm just waiting for all the early adopters to do Daz's bug testing for them.  When all the crap shakes out and it's working as well as 4.0 does for me; I'll probably go up to 4.5.  Primarily for the fact that autofit no longer hoses 4th gen morphs in clothes/hair/etc.  I could really care less if my 4.0 scenes don't open in 4.5 or whatever as once I'm done with something it usually gets trashcanned.

Well, I run 4.0 and 4.5 simultaniously on my pc.. (4.5 to test a 'certain plugin' we all know and love)

Now I did install DazStudio in C:DAZ4pro and in C:DAZ4.5pro

Before I installed 4.5 I made a copy of the C:DAZ4pro folder and let 4.5 uninstall the 'previous version'. After that I deleted the original C:DAZ4pro folder and renamed the copy back to the original name. Works like a dream. :)