A friend of mine gave me a couple of bags of Willamette hops that his neighbor had grown and frozen. They were about six months old. One bag contained hops that were dried and then frozen, the other bag contained hops that were frozen and not dried. I decided to make a small hop tea of each to compare the two before throwing them in a beer (i steeped a few cones of each in some near boiling water). The hops that were dried had a much more "hoppy" aroma and were noticeably more bitter. The hops that were frozen had a mild, vegetal aroma and were not very bitter. On a second occassion, a friend gave me some centennials that he had grown and frozen wet. They were about 3 months old. When I thawed them, I again noticed that they didn't smell very aromatic. I decided to throw them in a pale ale with about 5 min left in the boil. That beer ended up with almost no perceptible hop aroma, but it didn't have any off flavors imparted by the frozen hops either. I think the crystallization negatively impacts the "storagability" of hops in terms of their aroma and bittering potential, and you'd want to take that into consideration if you decide to brew with them.