Level Synch has changed this. Hard Mode moves you to 65, and even with gear I find you can't solo the gold boss elites.

Pre-update you could solo the Maelstrom Prison in Hard Mode if you had the skills/equipment. Now however, with level sync, you'll get your clock cleaned if you try it solo. Level Sync moves you up to 65. With a companion in heal or Tank mode you can take the normal mobs. But the Elite gold star ones will stomp you flat. And there's no stealthing by the Elites either. Plan to bring a full group if you want that last part.