Comparison of latest DAC chips

I own a Bluesound Node 2i which greatly improved sound after I added the Cat 6 cable.  I do not own a separate DAC but am told it would be the next step improvement.  I have done enough reading that it appears the two latest chips are the Sabre or ESS ES9038PRO and the AK4499.  The brands I have looked at are Sabaj d5($469) and a Topping D90($699).  I saw a great review on Audiocircle of the Sabaj D5 which is now a year old.  The Topping D90 is newer and I hear the build quality of the Topping as well as customer service are both better.   Other brands cost more and most don't use these new chips. 

Is there a difference in how these chips sound?  I would appreciate any comments. 
With bandwidth and sampling limitations, ringing and aliasing artifacts, all digital is only a facsimile of the original. R2R is no better than delta sigma in this respect, and has technical limitations of its own. 
Since most studios use Delta Sigma ADC's to create  PCM I'll guess the best way to convert it back is with Delta Sigma DAC's. The process used whether R2R, Delta Sigma,  Proprietary doesn't matter as much as how well the DAC is at getting a nice quiet accurate signal at the analog output. 
"It's hard to take stuff posted by people who take extreme black and white positions seriously."

Amen. Well said.

Most all music we listen to is recorded to PCM.
Quote from the DSD last year.
" Try teaching DSD recording to a PCM engineer... even the best... and you’ll find roadblocks and complaints of how hard it is to record in DSD."
Despite the marketing hype, there are almost no pure DSD recordings available to consumers. This is partially because up until quite recently there was no way to edit, mix, and master DSD files. So most pure DSD recordings that are commercially available are the rare DSD recordings made from a direct-to-analog recording, or those recorded direct to DSD without any post-production. There are some new studio software packages that can edit, mix, and master in DSD, but these are quite rare in the industry, and mostly used by small boutique recording companies. Most DSD recordings are, in fact, edited, mixed, and mastered in 5-bit PCM

Here are some statements from recording engineers.

"Recording in DSD and then converting PCM is only introducing noise into the PCM signal."

" Recording in DSD for a DSD only release, get the best from DSD."
There are almost no pure DSD recordings available to consumers.

" Recording in DSD to later convert to PCM, doesn’t make any sense"

Yes some DS dac lovers here are going to get testy over this post, but there it is.

Cheers George

Your quotes are all about DSD vs PCM recordings. What has any of that got to do with delta-sigma or R2R?