I have the Adios [10mm] and Saucony A6 [4mm]. I don't know if you really use/ need the heel of the Adios? The front of the Adios doesn't have a lot of cushioning, but definitely more than the A6. But I wouldn't recommend heavy heel striking in the A6 at all, it's like you say "a typical light weight flat".
I think that if you don't notice little pains you should just continue using them. And even if you feel something here or there it wouldn't necessarily mean you will get injured, maybe your body hasn't get used to the slightly different running motion yet.
I do notice the higher heel in the Adios, and there is more stress on my knees, especially if I ran in lower drop shoes the rest of the week. Your heel can't come down as much, so there is a tendency sometimes to land with a knee that remains too flexed, and the body in too much of a sitting position. If you know this, you can easily notice it, engage your hips, glutes more and correct it while running.