Good stuff in this article from Chris Price. Will Allen could really address the issues the Pats have had at slot corner over the past few seasons. It was better in 2011 (they were destroyed by #1 WRs) but Allen can do a number of things and that will make him extremely useful.
The [Will] Allen signing was a relatively under-the-radar pickup, but it appears that some around the league view the 33-year-old as a high-quality addition. He’s certainly developed a rep as a good slot corner in recent years — according to Pro Football Focus, he was in the slot for 419 snaps last season in Miami (tops in the league) and he yielded 0.81 yards per coverage snap for 3rd best in the league among slot corners. In addition, he allowed a catch once every 11.6 coverage snaps, a rate that was sixth best in the league at the position.