How's 7.5 running on new iMacs / Mavericks?

From the apogee website:

For customers with Haswell Macs
These January 2014 Installers fix an issue with USB audio quality on 2013 (non Fusion Drive) Haswell based Macintosh computers. They do not address a known issue with Macintosh computers with the Fusion Drive that has similar audio quality symptoms. More information about the Fusion Drive issue can be found on Apple’s support forums.

Seem that there is two distinct problems with Haswell Macs. USB and Fusion drive.
The Fusion drive problem seem’s fixed with 10.9.2 for some users including myself.