I think I'd have to echo what's been said above. I gained strength and mass on the 5x5, but that's almost irrelevant compared to what it taught me about training.
It got me off the machines for good, showed me that I could hit the same muscle group more than once a week and taught me how to manipulate volume to control fatigue. I don't think it's the be all and end all simply because no program can be, but I feel like it's given me enough knowledge to be able to evaluate other programs and judge how successful they're likely to be for me.
Once I've finished what I'm doing now (single factor 5x5, progressing to dual factor), I'll probably switch between some of the other programs like Korte and Smolov, and come back to the 5x5 as a mainstay.
It's got thumbs up from me.
(I also don't think that any of the options reflect my opinion. It is a good program, but it's useful to run other programs too.)