Updated impressions after finding right tips. Initial impressions were taken with the stock foams (not enough bass) and Comply 500 Comfort Mediums (congested bass, lower mids, more V-shaped).
Updated impressions taken with Comply T-500 (right balance of bass, lower mids, improved "air"
Air more apparent, less "gloss" and color. This is how a pro-EQ is supposed to sound.
The upper mids are no longer cluttered, nor are they recessed. They are "just right," substantial but uncluttered. Airy but not washed out.
I suspected the cost of newfound clarity might be sibilance, but the Pros power right through a fairly strident female vocal with no hype, no sibilance, no pained eardrums. I have to EQ this song on the W40s, not so with the Pros, which handle this track with apolmb.
This track literally gave me goosebumps. There's such a sense of "place" and an almost visceral quality to the strings, in particular. HBB mentioned the Pros lack some micro-detail compared to the Freedoms. I'm not sure if the detail is lacking or presented plainly. There are certain things you have to listen harder fro in front of an orchestra (looking at you, woodwinds), and others you might wish would calm down a bit. My experiences with this track are that the details are there (even the flutists' breathing, and the hiss of the phantom - powered mics!), but recessed as they might be in real life. With proper fitting tips, all the details are there, the bass hits quickly and with substance, and nothing buries anything else.
To be honest, I pick this track because I know a few warts in it, and can pick them out pretty quickly. Don't get me wrong, the mix and mastering are top notch, but the breaths, a percussionist dropping a mallet and the almost super-sonic hiss from the mics help me discover the limits of what I'm listening to/ through. I am in awe of how the S8 Pros handle it.
My opinion has changed a good deal over the last few days, as I've discovered proper fit, and tested the S8 Pros "live" with a track I wrote, performed, recorded and had a significant hand mixing and mastering. Far from the overly-present low-mids of my initial encounter, current impressions are of an honest set of IEMs that takes what's recorded and reproduces it relatively colorlessly. Is there a slight dip in the upper midrange? Yes, but it's not as drastic sounding as the chart might suggest, and creates the smallest bit of necessary separation between the lower and upper mids. Is the treble range "veiled?" No, it's honest, and there's a slight dip right where cymbals crash, making these a far better bargain for live monitoring use than I initially thought. There's no doubt in my mind that the S8 Pro will become, indeed already has become, my long-term in-ear monitoring solution.
If you want to use the vocal/ band mix I use to test for monitoring use,
here you go.