[Sprint HTC EVO 4G LTE] treblesum81:
I'm fairly sure it isn't the router since the phone is behaving the same way on my school's wifi and the one at the starbucks near my house. Also, I have other devices connected to my router at the same time as the Evo and none of them are experiencing the same issues.

I am willing to accept that there is a possibility the some or all of my 3G issues are related to the network upgrade, but I'm experiencing the extremely slow speeds over most of the city of Denver, and I'm guessing it would be unlikely that they would be upgrading 75% of the towers in the city at the same time. It also doesn't really explain the 3G service just shutting off randomly and then popping back on a few seconds later. That all being said, even if it is network issues, it just serves to highlight the lack of a reliable wifi connection.

As far as the back panel is concerned, I did install a micro-sd card there, and, since reading your post, I have removed it, blown off and dust / debris that might have gotten in there, and reseated it as snugly as possible. This didn't generate any sort of fix for the 3G issues, though I've not had a chance to test if wifi is working any better now. I did notice however that some of the gold filaments were discolored, so perhaps there is a manufacturing defect, though I'm not sure how the color of the filament could affect its conductivity.

I have done about 7 PRL / profile updates on this particular phone. I have also done a couple factory data hard resets through the boot screen in the hopes that it was just "glitching". Though the resets seemed to help, the effect didn't last, and none of the PRL / profile updates did anything to improve performance.

I did have a look at the *2 screen you mentioned and found that both voice and data had green checks by them, but I think this is only a check to determine if the connection exists at all and has nothing to do with quality. I do remember hearing about another testing screen you can get to through the dialer by pressing a sequence of characters which gives you access to a much more in-depth set of tests, but searching hasn't produced anything on that, at least with my search terms. That being said, I took a previous phone with the same issues into the sprint store and they told me it passed all of their diagnostic tests, so I'm not sure it would tell me anything different.

Luckily, mine doesn't seem to suffer from lag at all, just a really horrible connection. From what I've heard at best buy and sprint though, a huge number of people are having similar issues with this phone. The people at best buy even went so far as to try and tell me this was a "known issue" and therefore wouldn't be exchanging it again (this was the third time), to which I had to reply that I would then like a full refund and would be taking my business elsewhere. The way I see it, if a phone has a known issue, but not all of the phones are affected by it, you have to keep replacing it until I get one without the issue.

The encryption is WPA2 - AES and the router is running in "Mixed 802.11n, 802.11g, and 802.11b" mode.

I've thought about that possibility for sure, but the slow speeds and intermittent connections for 3g and wifi go, and have gone for all of the devices with this problem (don't forget, two of them were returned because they had dust under the phone's screen), all over the city with me, so, unless I'm a walking cell disrupter, then I think the issue lies somewhere in the phone.