Just my opinion. I dont think they have been overrated, but they have underachieved with the talent they have had. As far as Jackson, I believe last season he took a nice leap in passing but I still dont view him in the upper echelon of passing or reading defense. He is however usually one of the most overall talented guys on the field and exciting to watch. Also, I think he throws some of the most prettiest seam balls and sometimes even deep balls that I have ever seen.
Lastly, I also think the Bills have underachieved. Every year whether that is on defense or offense it seems we just need like 1 or 2 balls or controversial call to go our way and we would have been in.