The big concern with Keenan Allen is that in the end he's just not special. Solid, big, good hands, runs routes fairly well, but just not special. A guy that in the SEC would've been a safety. That's always been my biggest concern with him, will you get him in the NFL and discover he's just average when everyone else is bigger, stronger and faster?
As for why Cordarrelle Patterson has become the hot dot, it's because he's a junior JUCO transfer. Remember this time two years ago everyone knew who Cam Newton was and they saw him win the national championship, but he was still being honestly discussed as a possibility for the Dolphins at #15 overall and many a Dol-Fan thought he would be a reach at that pick. The reason is because Newton was a junior JUCO transfer. He was not on anyone's radar until his one year with Auburn, he was understandably raw and progressed as the season wore on, and it just takes a while for the market to fully get their arms around where exactly a guy like that is going to be valued. Keenan Allen has been around for years, on radar for years, people are used to him and have an idea where about he will value. Patterson is going to be all over the place and it won't be probably until March before we start to really get an idea where he's going to settle in.