I have the Canon A-1 and the Canon AE-1.
The Canon A-1 is a complex machine, at the time second only to the Canon F1, and its use requires a certain expertise. The Canon A-1 offers six programs of exposure and possible also take multiple exposures.
It is fully electronic and therefore will not work with the battery. Unfortunately, the battery lasts very low and it must always have a spare on hand.
The Canon AE-1 is very simple to use, takes a "shutter priority" and manually, does not have the battery problems plaguing the A-1, and not miss a shot!.
Both machines guarantee an excellent image quality.