Depends on how cheap and easy you can find them, compared to how fast you'll level up.
The 58-60 Tier 1-3 sets are mostly out. They look cool, but outland quest rewards are better than, say, the Valor or Lightforge set.
There are a few earlier sets though. The Imperial Plate set is a bunch of BoE crafted plate that's usually cheap, especially if you are or have have a miner. I was grinding my 70 hunter through Thorium mining when my pally was 50, so it made for a nice set of equipment to start Outland with.