I used to ride a fair bit in the NF. Have to go with Johnny on his assessment.
As far as the 'no weight penalty' for full suss, well LIKE FOR LIKE there will always be a weight 'penalty' for a full susser.
Given all else being equal, a 25lbs full susser could always be made at least a few pounds lighter as a rigid.
Just saying.
For certain routes, spending the extra £1000 to make your 25lbs full susser a 21lbs full susser would be less fruitful than spending that money making your 21lbs rigid a 16lbs rigid. It is all down to the terrain.
My preference would be for a lightweight xc with lockouts.