there are qute a few good fisheries i visit every now and then, not sure if they are all in northants but they are very close ( cambs border )
there is elinor, ringstead, ravensthorpe, eyebrook, grafham, ( cambs but close enough! ) rutland details of how these are fishing are in the evening telegraph on a thursday but i know that elinor is top quality and doing well on buzzers, hoppers and damsels
hope this helps cheers Daniel