I think it's possible they'll be a good team, but I don't expect it. That seems like a strong word for a team with this many question marks.
They have upgraded the secondary just by adding Carr, but we don't know how many growing pains the rookie will have. I think he'll be a quality corner, but a lot of folks thought Quentin Jammer was the cat's meow. We'll see.
Still have to replace Robinson's production from last year. That's not nearly as hard if Miles is healthy; Miles' health is probably one of the bigger factors in all this.
If Miles is hampered by injuries like he was last year and the OL doesn't improve, then I wouldn't expect much of anything, especially if they don't "strike gold" at the WR position again. Well, I would expect them to give up less late game leads, but I wouldn't expect them to have nearly as many.
Also remains to be seen how much more difficult this schedule will turn out to be if any. With parity being what it is, once you get past the top few teams matchups and strength of division often influence a team's postseason chances as much as their overall quality.
The flip side to all this is that if the OL plays significantly better and the key players on offense stay relatively healthy, then they should be a playoff/division contender.