I have to be honest, and I know I'll take some flack for this, but I like Watkins. Not saying he's great or even close, but he is serviceable JAG, and a DT rotation needs JAGs.
2 years ago, we tried to play him at the 1 tech, and he struggled. He just wasn't big enough to live there full time, and he got pushed around some. Later that season, we brought in Hankins (who was big enough), and Hankins allowed Watkins to play more 3 tech. He played well, and our overall line play improved greatly. I've always thought Watkins was a great 5th DT for a rotation. He can play both positions (though he's better at 3).
He's good enough to sub in in case of an injury to a player in front of him (which happens almost every week in the NFL).
Our mistake was letting Watkins and now Hankins get away (for deals we could have easily beaten, it's not as if either got a ridiculous offer). Hankins and Mazi at 1, Osa, Watkins and Gholston at 3, would at least be a deep and serviceable rotation. What we have now is not even serviceable, so I'm glad to have him, though I don't know what he has left.