Slasher makes a valid point about the MFX smaller diameter making the arrow closer to centerline of the riser, but I would think this would require less paradox to clear and make a given spine act weaker. At any rate, I'd try before I'd buy. Shot MFX for years and liked 'em alot. Now shoot TO's(because I'm cheap)and like them too. Be aware that there will be a difference in the throat diameter of the MFX nocks (Easton X,I think) and the TO, which is basically a Bohning Signature. So much so that I had to re-serve(I'm also picky). You can now get 100, 125, and 145 gr points in 9/32nds inch(Axis sized)for the skinny MFX. I think if you stay with 175 gr. that 5/16ths (TO sized)is as small as you'll find and you'll build up those back muscles pulling them out of 3D targets on an MFX shaft. Chucking them in a drill a tapering the back edge with a file will help a little. Good luck with whatever you choose!