No luck using greenpois0n in Ubuntu Linux running in VMWare Fusion on my Mac. It took so damned long just to figure out what I needed to install just to get it to run (you have to love Linux?), but finally I did, only to find that it wasn't ever able to either get it into DFU mode, or perhaps just didn't recognize that it was in DFU mode. Oh well. Maybe these issues with using it from VMWare Fusion are related to the tech problem they've had with the Mac native release. I'm done trying for now.
As for 4.1, I like it. The HDR photography is pretty nice, and I like Game Center a lot, even though it feels like a version 1, which of course it is. It's definitely the right idea. On the other hand there's the prospect that any updated version of Game Center will only come with new firmware, and that new firmware will make Greenpois0n a tethered jailbreak, and that means I won't update to it, so I'll be stuck on Game Center 1.0. Hopefully they can figure out another untether hack, though. I'm not sure if it fixes the proximity issue or not as I didn't really seem to have any issues with that, but that might be due to the fact that I don't really make that many calls. I'm mostly a data user.