Agree with Larry's assessment of TR5. I haven't used the standalone app, but I do like the new plugin GUIs, with a couple of exceptions: the 432 Mastering EQ and Tape Echo are too blurry-looking for my taste. Other than that, the modules look nice.
I was also pleasantly surprised by the reduction in CPU usage for several plugins, including the API EQs, the EQ 73, and SSL/Neve bus compressors. Oddly, on my system the EQ 81 is still pretty hungry but the 73 uses way less CPU than before. Sadly, the SSL channel strips are still too heavy on my system to use as a default processor on every channel of a mix.
I will be making more use of the APIs though -- they sound great and are now light enough to use everywhere. Anybody else seeing differences in resource usage between TR4 and TR5 plugins?
As for the new modules, I think they're pretty good:
My favorite is the Dyna-Mu, a fine emulation of the Manley Vari-Mu. I was hard pressed to tell the difference between it and the official UAD emulation, particularly at typical use settings where it's just giving a couple dBs of gain reduction on the master bus. This joins the T-RackS Precision and Bus Compressors (Neve and SSL models) as good choices for gluing your mix together.
EQual is a nice clean general-purpose EQ, very transparent -- beats the old Classic EQ hands down for usability. Gives Pro-Q2 a run for its money, perhaps even surpassing it soundwise, but it's tough to beat FabFilter's GUIs.
The One and Master Match are a little more hit-and-miss for me so far; sometimes I like what they do and sometimes I don't. Useful tools, anyway.
Overall, a worthwhile upgrade. Whether TR5 is preferable to Ozone is another matter -- I personally share the opinion that iZotope has a more advanced toolset, but there's a lot in T-RackS that is worth having. Now that more of the plugins are CPU-friendly, they're very useful in mixing as well as mastering. Ozone is not known for being easy on resources (but in a mastering context that's less of an issue). Both suites are excellent products.
Cheers,
Eddie