3GS software unlock vs. factory unlock

[uly]

Hello folks. I'm looking to buy an iPhone 3GS that I plan to with multiple carriers. Of course, an unlocked phone is a must. I have a few questions that I haven't been able to find a clear answer to despite (or perhaps because) of the overwhelming information out there...

So, I know that there are software tools that would allow me to jailbreak and unlock any iPhone myself. Are these tools (e.g. the iPhone Dev Team tools) reliable enough that someone like me, who is generally technically competent but otherwise a complete beginner with iPhones, to use properly?

Secondly, is a software unlocked iPhone fully functional? Will it revert back to being locked with future firmware updates? Given that there are free unlocking tools, is there any advantage in buying a factory unlocked iPhone?

Basically, I'm trying to decide between buying just any iPhone online or buying a factory unlocked iPhone from Hong Kong or Taiwan at a higher price. But of course, these are just things that are good to know, too.

Many thanks in advance.

[BrownGem]

I think if you are technically competent and always wait for info before upgrading firmware, should you choose to software unlock, you would do fine. Much help is also available on this forum. There are always immediate posts on this forum about how new firmwares affect software unlocks, on the day they are available. Read before you leap and you will save yourself some headaches on software unlocks. Factory unlock is less work so if you travel internationally it is convenient to not have to worry about compatible settings or changing anything to make the phone work. Dev team tools are quite reliable.

[uly]

Thanks for your quick reply.

Well, I am competent enough to be able to fix most of the computing problems that I encounter myself. But I don't always have the time and facilities for that, and I certainly prefer my iPhone to work reliably when I travel abroad.

So if I understand correctly, software unlock tools are still not a permanent unlock solution, and they still may be relocked on future updates? Is there a technical document available that explains the difference between factory and software unlocking?

If I do buy a factory unlocked iPhone, is there a way for me to I verify that it is indeed factory unlocked rather than software unlocked?

[BrownGem]

A software unlock is not permanent and any firmware update will erase the process. Of course you do not have to get the firmware update on it's release. Most unlockers wait until the Dev team comes up with a solution to unlock the new release..then they update. What usually happens is you miss out on the new features..which you may or may not want...and some apps may be compatible with new firmware and up only. Takes a few weeks usually for an unlock to be developed.
If there is a technical page on soft versus factory unlock I can't find.
A search on countries that sell unlocked iPhones can be had easily via google. Apple used to have a page listing model numbers and countries for factory unlocked phones but they removed it. Other than traveling to the country, it's off to Ebay.

[uly]

That cleared things up.

Last thing, though. I've already found a list of countries that sell unlocked iPhones, but it's cheaper and more convenient for me to purchase it from the US. There are quite some unlocked iPhone offerings on eBay, but how can I verify that a particular iPhone, either before or after I've purchased it, is indeed factory rather than software unlocked, other than just taking the vendor's word for it? Quite simply, I don't want to pay a premium for a software unlocked that I could have done myself.

[BrownGem]

Click HERE. There is a place at the top to enter a serial number. Maybe that will help determine if the phone is truly unlocked. Definitely deal with trusted vendors.
Edit: Many of the unlocked phones model number end with an A. Is it possible you have a trusted person to purchase from the apple store in a country that sells them unlocked and courier it to you? May cost you more but you can assured of it's authenticity.

[uly]

Okay. Many thanks for your help!