Have both the TA-A1ES and the Yamaha A-S2100 integrateds.
The Sony is slightly more refined, detailed and smooth than the Yamaha, albeit not noticeable unless you do a back-to-back comparison.
The Yamaha on the other hand is almost all of what Sony is while additionally it has a lot more power than the Sony & lower frequencies are stronger on the Yamaha.
I have to stress that I found the Sony to be quite underpowered as compared to the Yamaha - to give you some point of reference, keeping the same speaker, source and cables, I will have to crank up the Sony to about -35-30 dB (volume display reading) to get to the same spl as the Yamaha at say 11°clock position of the volume control. That's almost 70% of Sony to 40% of Yamaha's if that makes some sense. Speakers used for the comparison are the Dali Opticon 8s.
One other similarity b/w the Yamaha and the Sony I found is, both get equally warm/hot after about 30min of operation. I can understand the Sony is Class A and therefore runs hot, the Yamaha from what I gather is Class A/B yet it runs as hot as the Sony...I'm confident there's nothing wrong with the Yamaha as I did read quite a few reviews elsewhere that the A-S2100 do run hot, and there are not operational quibbles, so I just assumed that's how mosfet amplification works (the latest Yamaha A-S1100, 2100, 3000 are mosfet based amps)
Hence using the Sony as my bedroom system and paired it with Tannoy Mercury V4 (not an expensive pair of spkr, but I found the combo to be a nice match).
The Yamaha is paired to Dali Opticon 8 and, using a Marantz CDP 6004 as a source.
Bottomline - both are brilliant amps, I wouldn't trade one for the other!
Hope this helps...