For many ASUS Transformer Prime owners, the bootloader unlock tool provided by ASUS just didn’t work. Every time it was used, it spat out this error:
An unknown error occurs, which may be a network connection issue.
Please wait and try again later
For a person who finds rooting and modding important, this could be a disaster. ASUS realized this, and offers official unlocks by people sending in their Primes. There is a “special repair process set up for the affected tablets,” so we can assume it’s an issue that affects specific tablets on the hardware level.
It’s not a good thing, though, to send off your tablet for what could be a month just to get it unlocked. I can imagine that’s a poor user experience. Even getting one repaired for a month sucks (I’ve been there). But it might be worth it for some people.