I have never heard an Esoteric DAC, so Please keep that in mind.
Esoteric has a pride of ownership following that commands a premium in prices. The DACs that I have had recently are the Mytek Manhattan and the Bryston DAC3, both of which can be had for less than half the price of the older Esoteric that you are considering, and which are both are superb. Benchmark and Chord are two other companies that I would consider. DACs have really improved in the last several years, and my bias is that the older Esoteric will probably be bested by any piece that I just referenced. It would be nice to be able to audition to find out.
Another consideration is your room which you have described as suboptimal. DACs are just starting to come out which employ room correction technology. I suspect in a few years there will be more of these and of better quality. You may want to spend less this time around on one of the brands mentioned and await developments. Chances are that the DAC you purchase now may satisfy your needs completely but saving some cash now might leave you room for flexibility in the near future