BigBoss has written an article warning against the use of Ziphone. Below is what he has to say:

Question:
Could you please elaborate on the permanent changes caused by Ziphone? All unlocking/jailbreaking methods modify the phone in some way, at least they patch baseband, and pwnage patches bootloader. I know that Ziphone downgrades the 4.6 bootloader to 3.9 (which has been thought to be permanent until pwnage came out), but so does iLiberty+, iDemocracy and any other unlock method that is not based on pwnage.

Answer:
First off, iLiberty+ does not downgrade your bootloader by default. It downgrades you to 3.9 fakeblank which is easily reversible and not dangerous. This is not the same thing as 3.9 used by Ziphone! Ziphone downgrades the bootloader to 3.9 automatically. If this process fails, you’re done. This process considered so risky that Apple does not do any bootloader upgrades in their firmware packages! They could have put a stop to all the unlocks when 1.1.2 came out by having the 1.1.1 to 1.1.2 firmware upgrade upgrade old bootloaders to 4.6 but they considered this too risky and did not do it! Ziphone does it anyway.

Zibri has had so many releases that fix “type-o’s”. That’s just silly. The code is so sloppy and buggy. Some versions will unlock even when you did not ask it to resulting in a downgraded bootloader just on a request to jailbreak! Neat :(

Ziphone is also very dangerous because it does all the flashing (most risky part) during the first phase of the ram disk. During this phase, allocating too much memory can result in ram disk corruption. This is very bad. You want to minimize the amount of memory used as much as possible and you only care about stability. Ziphone doesn’t worry about this. Due to the technique used to boot the ramdisk, the memory is easily corrupted if you try to allocate too much of it. The result is that you are corrupting the very data that you are flashing!

iLiberty+, iPlus both use a smaller ram disk to flash. This minimizes the amount of memory used and takes great care to prevent memory allocations from corrupting the ram disk. Then these tools come back on a second pass to install payloads. This is done after the flashing is done where there is no risk.

As a result, several ziphone users have reported problems with no edge, no wifi, no bluetooth or a combination of the 3. In many cases this is unfixable. Zibri has added a wifi “fix” to his app which works sometimes, but this programs a bogus network address that is the same on every phone.

You can read the entire article at sleepers.net.