I did mine a couple nights ago and didn't notice much difference really.. the NSU failed or claimed to fail so I though awe crap i nerfed my new phone. Anyways let the phone sit awhile, took the battery in and out, it booted up fine, claims to have v2 firmware on it. not sure if there is really any test i can do to confirm it.
I tried to flash it again got the same error..
Anyone else hit this?