For light loads with mid-weight bullets I use both Universal Clays and AA #5, with a preference generally for the AA #5 in most cases. Perhaps it's because I've loaded with it longer, or have more of it on hand. The AA #5 just consistently delivers very uniform ballistics and accuracy with a minimum of load development and it meters so well while being practically immune to swings in temperature.
On the other hand, loads that I worked up fifteen and twenty years ago using Unique, I now confidently substitute Universal Clays in place of the Unique (at least in mid-weight bullet, fairly light loads) to get the clean burning attributes of Universal Clays. It's a great substitutiary powder for Unique in most instances.
FWIW!
God Bless,
Marshall