Just clarify, Ozone 5 also has the "gain matching" when in bypass and it is a really useful feature
I got Ozone 5 recently and can confirm that the free upgrade does mean 5 and 6 can be run side by side (ie 6 does not "replace" 5)
I am also really disappointed with Izotope on this "upgrade" and I think they may have shot themselves in the foot a bit
Not only the removal of features (albeit the less vital one but removing anything in an upgrade seems daft) but I definitely got the impression that the big selling point of "dynamic EQ" would be included in the base product
To not make this clear in the pre-sale marketing was not great
Also, the email giving me my Ozone 6 serial number had a link toOzone 6 Advanced - so it installed the demo of advanced, presumably to entice me to upgrade! - I immediately uninstalled advance and reinstalled the base version
All in all I think Izotope have not handled this upgrade well at all, which is a shame as I think Izotope are great