Hi Cyrus,
TAS development has indeed halted, so its performance has been consistent for quite some time. On the other hand, Roon has changed many times, each iteration sounding slightly different than the other, sometimes for better, sometimes for worse.
Judging from other servers that I have that run Roon, my overall impression over the last few months is that even though there are subtle and sometimes less subtle shifts in sound quality, Roon is always retaining its basic sonic presentation throughout the versions.
The bottom line is that the three systems are just very different.
In any case, as I have already and repeatedly found that XDMS royally outperforms both Roon and TAS, I see no point in re-evaluating this at this point. Honestly, there are far more pressing matters to tend to.
Besides, with the number of XDMS Alpha installations growing each day, I bet it's only a matter of time before you will see more comparisons!