Just a PSA, For those who think they can just look at retail photos to see if the sticks they are buying are a1 or a2 DO NOT trust it. Some retail photos are not what actually ships to the customer. So again, do not base your purchase off of retail photos, best thing you can do is google the model number of sticks you plan to buy and find customer photos of the kit to see where the capacitors are.
Also, i cant confirm or deny this capacitor theory, but my a1 sticks definetly have the capacitor above the notch and my 1 kit of a2 do not. So it would appear to be a plausible theory.