Looking At CD Players

I use an Oppo 105 as a transport into a Bryston DAC3.  Not only is Red Book great, but I listen to SACD in DSD.  Same chip as the Bryston CDP that you are contemplating 

Why a CD player ,when a good digital player sounds better ?
for Blu-ray concerts maybe 

I can comment on the Yamaha CD-S 2100 since you mentioned it specifically and not just because I own one...

It's a superb design and in addition to excellent sound quality offers a lot of flexibility. SACD, CD, USB DAC. The build quality is excellent. Its drive mechanism is something you'd expect to see in an Esoteric unit. Not a single piece of plastic in sight.

The only con i can come up with is toggling through the input selections is slower than expected. 

There are only a couple of pro reviews out there on the S2100, one from a new zealand magazine. Its pretty accurate and worth a search.

Not sure why you would want to replace your Oppo BD 105? 
I love my Oppo BD 105 and keeping it! I'm running balanced outs from the Oppo into my ARC LS15 Pre Amp But in the interst of me getting into Hi rez Streaming, and taking my music quality up a level, I just purchased the Exogal Comet DAC Plus and I'm going to add the Zen Mini MK III streamer that can also rip CD's to an enternal HD

I own both an Oppo 205 (stock) and a Cambridge 851C and the Cambridge is hands down better to my ears.

Because it uses a hybrid multibit/delta sigma, and for CD this is going to sound better than all delta sigma.

Even better again for CD is all R2R Multibit. as nothing does 16/44 24/96 DXD or CD conversion better than true R2R Multibit, latest discrete ones or the older no longer made chip converters like the PCM1704K ect ect

Cheers George