I just dropped Tampa last week, and kept Minny since they are the top D. After this crappy performance I am considering grabbing Bills D who just hit the ww in my 10 team. I really hate having 2 defenses, but that's also an option...
Consideration isn't needed. I highly doubt a league exists where BUF's D wouldn't be in the top 10 right now, not to mention on the WW.
Yes, seriously... What leagues are some of you guys playing in....BUF D on waivers??? The OP picked up top-rated MIN D "late in the draft???"

MIN was the first D off the board in both of my money leagues, way earlier than I'm willing to drop a pick on that position (like 6th or 7th rd). BUF D was also highly rated, should have had the highest score in any format week 1, and had a gravy match up this week against STL. Why would they be on the WW? MIN D is off to a rough start, but as mentioned they have a great playoff schedule and are worth hanging onto. BUF D is also certainly worth a roster spot. So is TB D for that matter. I wish I had these problems. In one league, I need a bye week cover for BUF & there's nothing but garbage available on waivers...