I love WaveLab, although I have virtually no experience with other editors. But I have had no desire to look at another, either. Some programs just give you the feeling that they really knew what they were doing when they put them together; WaveLab is one of those programs for me.
I suspect that the pro editors are much like choosing a DAW - they all have basically the same functionality, they just go about it in different ways. But that's just a guess, I don't have any experience in the others.
I'm an Adobe Audition freak. I made a temporary transfer to Wavelab, but couldn't handle the differences. I got the impression that Wavelab was just as good, but I'm just really locked into my Audition ways.
I just purchased Logic Studio, so I'll be giving Soundtrack Pro a try (it is included), though I have my doubts about it.
Audition has some pretty great built in plugins, including a very effective set of Noise Reduction tools. Also has a nice Multiband Compressor that I use from time to time. I couldn't be happier with the update to AA 3.0. A lot more bells and whistles, and a cleaner, less buggy interface.
There is nothing out there that compares. The simplicity yet huge amount of tools for mastering is incredible. If you can't make your songs sound commercial with this mastering software....then you should start recording from scratch again.