This is not supposed to be a thread about the relative merits of jailbreaking and not jailbreaking. In fact, this thread isn't about jailbreaking at all! It's a tutorial on how non-jailbreakers can preserve the ability to restore their phones to 3.1.3 even when Apple starts refusing to sign it after the next release. That is all.
There are clear reasons why this is advisable: it provides a safeguard against bugs and unwanted feature changes in future releases, and it will makes your phone more valuable at resale. Because these benefits are real and could be very significant, and because there is not a single disadvantage to doing so, I stand by my opinion that everyone, regardless of jailbreak status, should get their SHSH on file.
Again, this has nothing to do with jailbreaking.
Small White Car: there is no reason that jailbreakers should not upgrade to iTunes 9.1. I don't know where you got that idea, but your information is simply incorrect.
There are clear reasons why this is advisable: it provides a safeguard against bugs and unwanted feature changes in future releases, and it will makes your phone more valuable at resale. Because these benefits are real and could be very significant, and because there is not a single disadvantage to doing so, I stand by my opinion that everyone, regardless of jailbreak status, should get their SHSH on file.
Again, this has nothing to do with jailbreaking.
Small White Car: there is no reason that jailbreakers should not upgrade to iTunes 9.1. I don't know where you got that idea, but your information is simply incorrect.