AP's give the bigger discount, usually a straight percentage off. I think last year during value season it was about 35%?? Somewhere around there anyway. Not sure if it was that much for every season. We went from 77 rack to 49/night with AP at value resort. I do know that general code (no ticket or
AAA required) was 55/night.
AAA is 20% at value and moderate during value season and 15% during regular season. I think deluxe runs 15% during value season and 10 during regular season but not entirely sure on the deluxes.
Now the advantages and disadvantages:
AP disadvantage is that they are not guaranteed. There could be no code during your time frame or for your resort or they could be gone. They do tend to be taken up quickly. And the timeframe they release them out it can be cutting it close to when your vacation time. People now are waiting to see if they can get an AP rate for the end of April, no codes released yet, don't know if there will be or not. So it can be cutting it tight and they might not come.
Generally if you plan on coming back again before the APs expire then its good to get them because they will save you money on getting into the parks. I think 9 days is the break even point. Really APs should be bought this way and any extra discounts are just gravy.
APs can be dangerous though

you will try to plan as many trips as you can (even if you think you won't, you will

) before they expire which in turn will cost you more because you are down there more. Believe me I managed to sqeeze in another 4 night trip that I had no intention of doing because I knew I could and wanted to get the most out of them before they expire.
Now general codes aren't that far off from APs, as I said above 55/night as opposed to 49 with the AP and there is no ticket or anything required. Now these aren't guaranteed either and run like APs do, can cut it close or not come out at all.
AAA well you can book in advance and know that you will get one. They do have a limit on how many rooms but if you want to book enough in advance then you are more likely to get one and you can budget accordingly. I am paying 107/night now at a moderate during value season instead of 134. Its 20% but its still better than rack rate.
You do need a membership for AAA but its worth it plus the roadside and other travel discounts that come with it.
So I hope that helps some.