You need to make your own decision, but I'd hoped the first post was not that confusing. In your scenario, once you move to 5.0 you are stuck there. If you mess up your jailbreak once it is released you will have to restore to the latest firmware (which will probably be 5.0.1 or newer at the time), and you will likely lose your jailbreak as blobs are worthless for 5.0.

