I'm new to this board and have read a lot of good stuff so I though I would try to get some info. I'm having trouble chopping straw with my 1688 since I installed an afx kit on the front of my rotor. I've tried everything. I started with new knives and the taller concaves, but apparently the straw must be in too good of shape when it gets to the chopper. Is that what's going on? So I'm wondering if putting in a TSR chopper would help??? Is there a gain in performance over the factory chopper? How about the Redekop MAV? That looks like a whole different animal all together. I'm also thinking of updating the straw spreader as the factory one only does about 20ft and I have a 25ft head. Not good when the straw isn't chopping well. CIH has a kit to make it like to 21xx, 23xx series. Anyone done that? Sorry for such a long question. Any tips will be appreciated. Thanks.