Our run D will be good this year. Ahmad Brooks, Domata Peko, Rashad Jeanty and Justin Smith are good against the run. I'm still concerned about our secondary but the talent level has improved, it's just a matter of putting it together.
In terms of record I think the Bengals could be +4 or +5 on last year which would make them one of the more improved teams but in terms of additions we aren't one of the most improved... Much of it relys on regaining health and the growth of our young players as well as luck/schedule.
EDIT: I wrote this before seeing the second half, you obviously didn't watch the game. We gave up only 10 points with 7 minutes left in the game and the defense on the field always had 6-8 players that won't even make the team so they aren't considered depth. Marvin White played the whole second half and was making plays, Eric Henderson/Rashad Jeanty/Andre Frazier all played DE (they're all SLB's) and occasionaly Chinedum Ndukwe played. Other than that all players who won't make the team.