I will try to answer the last couple of questions...
First thing you need is to retrieve your MSL number. There is a .exe file called "GetSPC" out there. When you run this, input your HEX ESN number, this will pop out your MSL.
Go to
http://corolada.com/prl/ and download a file. I have sprint and use 20232 for now, seems to be working well. Save this file to your computer first, then sync it to your phone.
Go to your phone app, hit ##778# go to edit and input your MSL number.
Hit View Info and select PRL
Go to Update PRL File and browse for the file you just synced
Hit View Info and select Modem Settings
This is where I am still testing, but I like the results so far. I changed Preferred Serving System to Roaming Only. Then I changed Preferred Mode to Digital only. Oh, I also checked with Sprint and my SERO plan does not have a roaming charge. Confirmed it yesterday, so will see what happens on my next bill!
With these changes, I have had great results! Battery life lasted all day, nothing different from what I have experienced. The reception is great after the changed. Before, I would drop about 20% of my calls, most of the time multiple times in a row. I would also miss calls, which really sucks when someone is picking you up (blah blah blah). I now have GREAT reception, currently 5 bars on AVERAGE (up from 1.5 average).
The only problem is I am losing EVDO, like not getting it at all. With Roaming only, I can only get an 1x connection. It limits my other functions that require more bandwidth. After the OpenDNS hack I was clocked at 350 kb/s(?). With the 1x, it's about 35kb/s (?).
There is a setting under Modem Settings/Preferred Mode called HDR Only. It is supposed to use EVDO only when needed, but I tried this and didn't really work for me. My phone "Struggled" to maintain EVDO and I was missing calls. I would want it to maintain a 1x connection until I use programs that need a bigger bandwidth, but that didn't happen.
Does anyone have any experience about these concerns, or does anyone know a way to designate particular programs what will switch to EVDO?
Hope this is helpful!
1. Yes, you will be in constant roaming with the using the settings I am using
2. You can tether in roaming, just painfully slow. EVDO is a must with the OpenDNS hack.
3. Yes, the PRL file is removable. After you "update" your PRL, you can "update" it back to what is was before. Take note of your PRL under "PRL ID". If you can't find it in your phone, download it again from the website!