First, a hearty welcome to CPDARNOLD!
I've used the UUK for many years (mine has a number like 12 or 17, can't recall exactly). I showed it to Guro Dan Inosanto, who was apparently consulted by Mr. Szabo at one time or another (Mr. Szabo trains with one of Guro Inosanto's top instructors). Guro Inosanto emphasized the unique qualities of the knife, especially in reverse grip. I've used the UUK trainer in lots of classes and it really shines for reverse grip. No other knife I own thrusts as well in reverse grip, owing to the pistol grip angle of the handle. The knife comes razor sharp on both edges and is very solidly constructed. Grip is quite comfortable for me, anyway. Good kydex sheath too.
I think the UUK is not only a versatile fixed blade defensive knife, but a unique collectible.