These dishes are in very common use by the microwave crowd. I have one I picked up for $10 that I use on 10 GHz weak-signal modes. Very nice dish; the offset feed dishes are preferable because the feed is out of the way of the visible area of the dish.
If you have the feedhorn that comes with it, it's a relatively simple matter to place the feed for your band of choice at that location.
See the W1GHZ On-Line Antenna Book for more info:http://www.w1ghz.org/antbook/contents.htm
73, Zack W9SZ