Is Super Aggregated VLANs Brocades version of Q-in-Q? If any, what are some of the major differences between SAV and Q-in-Q?
Same thing, different (older) branding. Normally for 802.1ad there's a C-TAG and an S-TAG. The C-TAG (customer tag) will have almost always have a value of 8100 set in its TPID (tag protocol identifier) field. The S-TAG (service tag - the tag on top) will have a separate set of fields (same as the C-TAG: PCP/DEI/TPID/VID bits) and its TPID should be 0x88a8 by the standard. A lot of vendors will let you set the value for the S-TAG TPID to something arbitrary (Brocade likes to recommend 9100 a lot - probably for compatibility reasons). Some vendors (Brocade also being one of them) will let you also set the C-TAG TPID but I can't think of any useful reason why someone would want to deviate from the norm of 8100. It's more common to want/need to change the S-TAG TPID value.