I have a USPc .40 variant 1 and the safety has a fairly distinct click in both the safe and fire directions on the switch. I wouldn't describe either as particularly "long" but to each his own. My gun is fairly new though and you should keep in mind that every gun will wear with time and become less stiff in many respects.
My only concern though is that you may be mistaking the decocker portion of the lever with the safety. The USP has 3 positions to the safety switch (depending on variation). The upper most position is safe, the middle is fire and a spring loaded decocker is at the bottom most travel of the lever.
I'm sorry if I'm stating the obvious to you but I've never really gotten to shoot a broken in USP but I'm told they age nicely and last a damn long time. I like the safety and decocker on the USP and the fact that you can carry this pistol "cocked and locked" like a 1911 is an added feature.