Is 44.1/16 a limited format? Of course it is, as is every other transfer medium/protocol. As with every category of audio gear, there is a dizzying mix of art and science to achieve the ultimate "sound" of any piece. More than solid state, more than speakers, more than wires, or any other thread of the Great Fabric, digital is still cutting its teeth. Is higher resolution better? Sure it is, there's more information there to be extracted. Does that make redbook-standard bad? No way.
CDPs are immensely complex beasts. From what I read, there still is a lot of "black box" hiding in that little, black box. Designing to the science aspect of line-level delivery is the natural tendency, plus bits is bits. How has that bias leaned in the last 20 years of redbook design? Almost exclusively, it has found methods to extract the tiniest of those bits and lay them bare on the stage. Result? Amusical products leading to threads such as this.
One backlash has been the non-oversampling architecture now favored by some. This seemingly archaic "solution" is touted as anti-audiophile by proponents and shunned by others as lifeless.
Does this mean nobody has it right? Or, the optimist may counter that both are working on getting it right. The art is coming to redbook. Finding the balance of detail extraction and smoothness/tonality is coming.
Do tubes help with digital? I think so, but the Attraction DAC/Sig. 70 amps would be a very nice, all SS combo.
CD standards are fine properly implemented, and THAT's the trick.