re: How much better would a Swarovski Z3 4-12x50 be than my current...

I have a Swaro 1" AV 4 x 12 x 50 with the TDS reticile and it is by far the best scope I have ever owned. I also own several Leuo VX111's, 2 Zeiss Conquest, 4 Burris and it is not even close on the clarity of the scope in the late evening or just after dark. They will make a difference to you. Much better than Nikon but the cost is about double what you pay for the others.

If you are willing to spend the money, you cannot go wrong with the Swaro.

Also, I agree that S&B makes one of, if not the top, scope. But they do not make any 1" American style scopes. All of them are the 30 mm variety. So if you want to compare apples with apples, you must compare a 30 mm S&B to a 30 mm Swaro. If you do, I doubt you will be able to tell much difference between them.