Gevey Ultra downside/disadvantage?

[spotsphill]

So I'm running a AT&T locked iPhone 4S and I want to preserve my potential unlockability (currently on iOS 5.0 & firmware 1.0.11) so I can sell it before the next iPhone comes around. With redsn0w not being available (and as far as I can see no unlock in the works), what is the disadvantage to using (and selling the phone) with the Gevey Ultra S? I imagine it could even be a selling point (e.g. "No need to worry about the unlock being lost in the event you accidentally upgrade to the latest OS version).

Is there something I'm missing? Thanks.

-Phill

 

[Applejuiced]

Gevey sim interposers don't work on any firmware and when apple releases new firmware and bb versions they patch the gevey unlock exploits.
So the unlock can be lost if one accidentally updates.

 

[spotsphill]

Ah, ok thanks. Good to know. Any other downsides? Any performance issues?

 

[Applejuiced]

Nothing bad as far as I know.