After investigating a bit, I'm starting to conclude that it's possible to get your 44.1 / 16 audio to sound really close to what the high res version sounds like. That's largely thanks to dithering. I can get my mixes to sound almost identical in 16 bit to what they do in 24 by using the appropriate dithering setting. That said, they're still not quite as good as the 24 bit bounces. Theres a very slight loss of depth. But it's really close. And it's really close while listening with my Lavry DA10 -> B22 -> K1000s setup. While that's not the absolute most resolving setup, it's an extremely revealing way to monitor. If I listened with Sennheisers, I doubt that I'd be able to hear a difference.
Here's part of a post by a mastering engineer on gearslutz.com. His conclusion is consistent with mine.
"I've been doing classical editing, mastering, and other music production "in the box", using floating point math, for over a decade now. Using high resolution converters, I can use a simple flat spectrum TPDF dither in the monitor chain, and not worry about changing it until the end of the process when it's time to make a CD. Until then, the dither is only needed to get from my workstation's internal floating point representation to the fixed point format used by my control room DAC. But when I want to, I can tell the workstation to use POW'R, TPDF, or even no dither at all, and to throttle the word length back to 16 bits on the way to my DAC. That way I can hear what the CD is going to sound like if I make a particular dithering choice. To me, it's a case of "choose your poison", because the result is always a bit worse than my high resolution feed. "
Some heretical ideas about dither... - Gearslutz.com
As far as DSD goes, I've seen several people describe it as smoother and more analogue sounding than PCM. Having never heard DSD, I'll just have to take their word for it. But I do wonder what might account for this difference. The only thing I can think of is that the DACs these people are using do a better job with DSD. Perhaps DSD DACs are currently a step ahead?
But technical stuff aside, it's assuring to pick up a release on SACD or DVDA. Because they're supposed to be audiophile formats, they tend to be extremely well mastered recordings. But it's infuriating that they'd put a different version on the CD layer of the disc. I was going to get that Dark Side of the Moon SACD. But after bigshot's comments, I think I'll pass.