Anxious to hear the answers. It seems the serious guys swear by the M1 for long range. I am not that serious, so I bought a CDS, and have practiced quite a bit with it out to 500 (don't plan on shooting farther than that...) and I can't imagine a system being simpler. Mine is in place for that shot that present itself above and beyond the 300 yards or less where most of my game is taken. Soooo with what little exposure Ive had, and the guys Ive asked on this forum whom I trust, it seems like the M1 for serious repetitive long range shooting, and the CDS for us simpler souls......
