Is this true if you use ziphone only to jailbreak it? Does it change it the same way if you only jailbreak?
No! Just jailbreaking does NOT change the bootloader. I just did some research and checked my own phone for reference.
Also there's some misinformation around here. I've heard of a lot of people taking in their iPhones for service even after they unlocked it and Apple accepted them. Also the vast majority of people out there just Jailbreak and don't unlock their phones.
Even I've taken in my phone for service (before it was jailbreaked) and the Apple tech didn't bother checking my bootloader before handing me a replacement phone.
Nah, it's big to like 1% of less of the diehard hack0rz who don't like the near pitch perfect form and function of the current iPhone OS and would rather downgrade it to some clunky crappy OS and kill it's ability to do certain functions, you know, like acting like a PHONE (the knuckleheads not clear on the Phone part of iPhone). Sure I could then put my Sprint sim in it, but then I just lost my ability to get email pushed to it, my browsing experience is going to suck on any other browser but Safari, no more syncing well with iCal, etc.
These morons are like a cult who just don't like Apple and AT&T and feel the need to whine about and break stuff to feel smug and self-important. They are exactly like the people who are all whine whine whine "OS X won't work on my Dull Chumput0r, Apple should make it's OS free (and kill their hardware line) whine whine" geeks from good homes that listen to repetitive same sounding angsty songs by wimpy white "rappers" [sic] like Linkin Park (a bunch of ******* from good homes who need a good smack up side their heads). But reality, how many people are out there running OS X on a peecee? Yeah, like .00001 maybe.
That's really condescending. Some people out there just like playing with their gadgets. Most people out there who have unlocked their phone live in places that haven't yet released the iPhone.
The iPhone won't accept a Sprint SIM, and my jailbreaked phone operates just like any regular iPhone but with added functionality. I still use Safari, Calendar, and my iPod portion of the phone, and I get to have a ToDo list, Sudoku, and a virtual Piano on my iPhone (I'm a pianist, it's fun). I'm also looking forward to loading Linux up on my phone. Just to play around with it, use it as a WiFi tablet for a bit, and then reflash it with the regular iPhone OS. I've hacked my PSP and my old XBox, and enjoying those too.