In terms of elapsed time for a Shroud completion, the dark monk was and still may be a very good choice. High saves and possibly AC, Shadow Fade all add up to less incoming damage, one less healer= 1 more dps... very good damage against portals (full TOD and decent non-crit base damage) which are the biggest single time sink.
These factors do not translate into anything like comparable performance in the more important (at least for gearing a monk) areas in Amrath.
A well geared dark monk will be solid DPS, the problem is that the dark monk trying to get geared out is sub-par in Amrath, which is the only place he can become well geared.