I had the same dilemma. I initially replaced them with a two ski travel quiver composed of a set of Stockli Laser AX and a Blizzard Rustler 11. These are both great skis. However, what I missed was all-round capability in spring snow, as well as the ability to travel with one set and deal with most anything not deep powder. So the Rustler has turned into the powder ski and the Laser AX is what I use at Deer Valley, Sun Valley, places like that.
So, having a bad case of Ski Acquisition Syndrome, I did some demo days and wound up picking up a set of Kastle FX95HP. They aren't quite as turny as the UCs, but turny enough, they have fantastic edgehold like the UC, and they do much better in bumps due to the rocker. They are very stable. They aren't great at my size in 6" +, but frankly the UCs never performed for me in powder as you would think given the width of the shovel. I found they tended to dive easily. And I still have my blizzards for that.
Th Enforcer 100 being recommended is a great ski as well, but when I skied it I did not get the hardpack performance out of it I got out of the Kastle. In spring snow I think either would be great.
Still one of the best days I had last year was skiing my UCs very late in the season at Squaw. Big soft bumps all the way down KT. They were so nice. I actually look forward to getting out the rock skis these days since they are UCs.