Craig Dahl--anything special here?

I've got TJ Ward, William Moore and Craig Dahl as my Safeties  (I have 2 safety spots and one DP spot, where I can play either Henderson/McCarthy--who are both out this week--and Dahl).

I noticed he was listed as a DB2 in the "Rest of season rankings" (and as the #14 DB for this week with a favorable matchup) and listed as a lvl 4 DB in the Starts and Sits column.
However, I dont see the value.  In 2011 he had 61 tackles and 1 interception.  He is on pace this year to do much more than that with 19 tackles so far.  However, he doesnt seem all that great (at least in the last 3 weeks) compared to so many other safeties.

So I have two questions:

Is Dahl someone with lots of potential who hasnt really started to produce yet?  What am I not seeing?

and since Atari Bigby is on my WW this week, would Bigby be a better pickup over Dahl for the rest of the season?

Dahl isn't an exciting player, but he's dependable and consistent at a position with a lot of week to week volatility. I don't think he's gonna produce at a greater rate than he's been producing, However, at his current rate, he's projected to rack up 96 solo tackles. Would you take that out of your safety? Obviously that's an extrapolation, but you get the point. I prefer consistent tackle producing safeties and Dahl fits the bill.

I like Bigby as well. Both players are ranked about the same in my book. I may give the slight edge to Bigby though.