A few things.
Trumbetti was the most athletic DL we had last year. He's productive in almost all games he gets snaps. In fact, BGi did a series where they looked at snap counts and based on production to snaps, he was the most productive DE we had over the last 1 1/2 seasons (It was done before Okwara went on his streak) when it comes to QB hurries and was pretty darn close on TFL. Now, QB hurries don't get people all that excited, I get it. But QB hurries are significant especially in the era of spread offenses.
Hayes was intentionally RS last year. The depth needed when Jones went down was at NT and Cage/Tillery were able to fill that gap. Plus, Sheldon and Rochell weren't coming off the field. I'ts going to be interesting to see if Tillery gets more snaps at 3T with a healthy Jarron and no Day. Is Hayes able to get his snaps in too. I've always been high on Hayes physically and still am, it just seems like he hasn't been able to put it all together yet. Some guys it takes a few years, no harm in that, yet
On the defense as a whole. A lot is going to be on the shoulders of the LB's, IMO. BGI did a piece where they highlighted some plays from 2014 of Morgan and Jarron Jones so readers could understand what they could bring to the table in 2016. No doubt about, Morgan could be an absolute stud if he can figure out the defense. He can do things that Schmidt couldn't so if we get that play or get BVG to run a scheme those players can handle, I can see this D being quite good, the talent and athleticism is there. With that said, I don't expect BVG to change much and I'm nervous we are in store for a 2014 like defense.
I have normal worries about the offense. Where does the production come from at WR? Do the new OL click right away? etc. However, in general I think that there is so much talent there, that I can't see it faltering and I truly think that the offensive staff is in a sweet spot with Kelly, Denbrock, and Sanford. Don't see those guys missing next year. Wish I felt the same about the D.