I noticed today my 1st gen iPhone -- running 2.0.2 -- was getting weaker signals than last week, on the very same spot I sat here in the office.
And I remembered this weekend, right after QuickPwn for Mac was released, I ran it just to have proper files on my phone -- I was one of the eager iPhone owners who used QuickPwn for Windows with 2.0.1 iPhone OS right after 2.0.2 was available to Update on iTunes.
So, I took my MacBook, copied 2.0.1 bundles from PwnageTool, and added them on QuickPwn for Mac. Grab a 2.0.1 firmware image and QuickPwn'ed my 2.0.2 phone back with 2.0.1 files.
Guess what? Signal raised a lot, enough to let me be able to connect back to Internet flawlessly -- just as it was last week.
So, yes, 2.0.2 OS do reduces iPhone power transmition levels. I did not moved a bit my phone and the issues I was facing 5mins ago for the entire morning, just disappeared.
I will try this with some other work mates which were complaining about signal power, and will let you know my findings.
Also, if someone wanna give it a shot, feel free to let the world+dog to know about it.
Hope it can be useful for you too.