Voxengo has a new one called TEOTE (“That’s Easier On The Ears”). In the bit of testing I did last night I liked it more than Gullfoss. It’s based on multiband dynamics rather than EQ.
I haven’t tortured TEOTE with harsher high-resonance stuff yet, but I did throw some busy FM pads at it that were a bit crowded in the mids, and it cleared them up a little more nicely than Gullfoss did. It also can give a little more punch and pluck to punchy and plucky parts, though not as strongly as a more standard compressor might. And that was before I read the manual, which offers some helpful advice.
Automatic tools like this are great for my workflow. I don’t multitrack, so mixing is just a part of the performance/recording process. I try to keep that fast and spontaneous, not getting meticulous until later editing and mastering steps. But it takes almost no time to slap Gullfoss or TEOTE onto a channel and hear whether it helped… and then decide whether to just let it work its magic, or target that part for some specific correction.
I do the same with the DDMF MagicDeathEye compressor – you pretty much can’t find settings that make the sound worse, and often it’ll simply sound 3% better for no effort. (Gullfoss and TEOTE do need a little tweaking or they may overhype the high end or sound a bit unnatural, but they’re easy to rein in if that happens.)