I'm going to sound biased, but go with Sargeras-US. You mentioned looking at Turalyon, but coming from a person who has played on both, on Alliance side, you will get more out of Sargeras than Turalyon. Turalyon has few decent guilds, next to no PuG activity, and no pvpers. Sargeras has numerous quality guilds, a vibrant PuG scene, and a respectable PvP scene. Transferring to Sargeras after playing on Turalyon for two and a half year was a breath of fresh air. The complaints about queues are overstated, at least on most US realms. Sargeras has the 2nd highest number of Alliance players in US but only occasionally gets a 5-10 minute queue at prime time on Tuesday nights. Even then, 99% of the time, there is no queue.