Can I log instrument flight time for currency purposes in an Advanced Aviation Training Device (AATD)?
From what I can tell, the Advisory Circular is outdated. It was issued July 14, 2008, while the most recent update to 14 CFR 61.57 was effective Nov 15, 2013.
When the AC was issued, 61.57(c) did not contain the wording specific to Aviation Training Devices (effective 11/17/2003). That language was added in the version effective 10/20/2009, and the AC apparently has not been revised since that point.
At this point the regulations are more specific (and regulatory) than the Advisory Circular. You should be able to log recent flight instrument experience in a ATD based on 61.57(c)(3), or the subsequent subsections that pertain to mixed currency.

(3) Use of an aviation training device for maintaining instrument experience. Within the 2 calendar months preceding the month of the flight, that person performed and logged at least the following tasks, iterations, and time [emphasis mine] in an aviation training device and has performed the following--

(i) Three hours of instrument experience.
(ii) Holding procedures and tasks.
(iii) Six instrument approaches.
(iv) Two unusual attitude recoveries while in a descending, Vne airspeed condition and two unusual attitude recoveries while in an ascending, stall speed condition.
(v) Interception and tracking courses through the use of navigational electronic systems.