I noticed you only covered snowbreeze, a Windows-only JB method, so I'll post my experience with the available Mac tools:
First I tried to JB with Redsn0w. It didn't work. It got to the point where it should have copied files to my phone, but instead said Unknown Error and failed. I tried 3-4 times, with the same result each time. I've used Redsn0w before and always had problems with it. This doesn't mean it won't work for others, but it did not work for me.
Finally I gave up and went to use Pwnage. I used one set of instructions and found that my phone would not activate. I could not make or receive calls, no data, no text, nothing.... not good. I kept searching, flashed back to 4.3.1 and then found these instructions:
iClarified - iPhone - How to Jailbreak Your iPhone 3GS Using PwnageTool (Mac) [4.3.1]
Step 6 was the one missing from my first directions. That option, as far as I'm concerned, should be unchecked by default, but it is not, so if you use your iPhone on AT&T or another authorized carrier worldwide, then you need to go in and uncheck that option.
Long story short, I finished it up, got my jailbreak, did a restore from backup and I'm good to go.