I adopted it wholesale into my campaign at the time, and within a few weeks realized it was pretty uneven so we started to pull stuff back. As I recall, by the time the dust settled on our playtesting, we kept:
- the new races and level limits
- the thief-acrobat
- some of the spells and magic items
- field plate and full plate, and most of the other new equipment
- a changed version of the social classes
... and everything else we more or less junked. We did have some classes for knight-types and barbarians, but not from UA. Even that which we kept was lightly to extensively house-ruled.
Basically, Unearthed Arcana and Oriental Adventures were the two books that killed my innocence as a DM - they taught me I couldn't just buy a TSR book and assume it was balanced or even finished, respectively. Not a bad lesson to learn, but not much fun at the time.