I continued my solo efforts with the next logical step: I moved on to Zangarmarsh and defeated the five-man instances there. Again, as with the Hellfire Peninsula dungeons, I expected no challenge from them and they were easy mode. There are simply no weird mechanics in these fights that could cause a problem. I didn’t get any worth-while loot either.
As a side note, you do get pretty good reputation gains from the Hard mode dungeons. I think I got 5-6k Cenarion Expedition reputation for the three dungeons together, plus maybe 20-30 Coilfang Armaments. I didn’t even do a full clear of any of these dungeons.
I’ll want all reputations maxed that I can do with reasonable effort, but the Cenarion Expedition is one of those reputations where it makes more sense than just to get the achievements; the Cenarion Expedition sells the Cenarion War Hippogryph mount to those who reach Exalted.