I have only compared the general sound quality, and I have not done a full analysis on the compression, etc. I hate to use the word same without a more technical analysis.
A few comments on the download. I compared the HDtracks to the 2011 remasters and the original masters. The HDtracks sound is very similar to the 2011 remasters. I should mention that your not getting a "complete" set of Smiths discography as the download does not include all of the albums that are included in the Smiths "Complete" box set.