I am still lvl75 LUL
But yeah I am in no rush in doing any of these raids. They are so fkn ultra easy for even super casual players and will get so boring so fast that I see no reason in why I would rush anything. Naxx10 is as easy as a 5man heroic dungeon, but it's also fast and thus fun. Naxx25 is a snooze fest and only Maly/Sarth are fun, but they are also just 2 bosses.
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As others have said, Sarth was a 3.0 boss. Halion (Ruby Sanctum) was the boss that was released in 3.3.5.
The raids are still super easy, despite all the buffs. I am not joking when I am saying that Wrath Naxx (the original wrath version) is easier than any of the LFR's in SL.