With further listening, I found the 10 ohm setting to continue to sound excellent, but I did find the dynamics to be somewhat compressed. I tried 800 ohms, and the dynamics were much improved, but the air around the instruments and vocals was significantly worse. Also, instruments such as piano and saxophone became much less 'real' sounding and took on a more metallic/electronic sound. Surprisingly, the noise floor also seemed to become increased. Maybe for this reason, or maybe something to do with the increased dynamics, the instruments became less located in space...everything kind of ran together.
So, I switched back to 100 and then 30 ohms, and I found the latter to give the best compromise between the clarity and correct space of the 10 ohm setting and the dynamics of the 800 ohm setting. And, it's not so much of a compromise...it gets both clarity and dynamics close to just right for my ears (and I think it's pretty accurate as well).