It’s been a while since there has been an update to this, but that might be because there is not much to improve on. You may have noticed most of the plugins I own are from the “big-name / expensive” guys, but PSP is that rare indie exception.
Those graphs look pretty clean, a might too clean I would say. Not that I have a 1950s RS56 laying around, but I’m going to guess it was a bit more noisy and added a bit more distortion than this plugin.
The interface is pretty straightforward but you have to pay attention to the controls, there are a lot of (non-intuitive) things going on. This is for someone who wants to listen their way through cleanly touching up a sound. It’s subtle. (Or musical. People always use that term—it just means you can’t do anything really drastic to the sound.)
It doesn’t get any cleaner than this, or any flatter of a frequency response. The hardware version costs over $10k, of which 75¢ must have been devoted to the interface. Seriously, we can’t do any better than this? And it is really awkward using it on the computer screen. Still, it’s about as good sonically as you can get if you are looking for the clearest possible sound, so screw UX.
I’m not really sold on this. I personally like to avoid EQ “at the end” of the process, because it always feels like you are fixing something that you should just fix somewhere else. So why not just go and fix it? These all-in-one solutions seem to be more about trend than function, but then I’m not a mastering engineer. It really cleans out the high and low end though! You don’t even have to do anything but insert it on channel.