It's still discussable if the dual-core powered HTC One XL is the better HTC One X but one thing is for sure, AT&T's One XL version, AT&T sells since last week as the AT&T HTC One X, is pretty locked-down. While HTC is offering the bootloader developer unlock for all new Android phones, AT&T has asked HTC to not allow unlocking the bootloader which keeps users away from installing custom ROMs on the device. Nevertheless, and while this is not a bootloader unlock, the first root solution made it to the public; which allows users to install system apps which requires root access. The solution is pretty straight forward and installs Busybox and SuperSU for rights management.
After a couple of reboots, the AT&T One X is rooted and finally allows to install such apps like System App Remover, to get rid of AT&T's bloatware.
However, it should noted that the One X bootloader says "---TAMPERED---" after you have rooted your device which means AT&T knows from now that the device was "hacked" which might have impact on the warranty. So better be sure you know what you do before rooting your device!
Cheers ~ Arne