Well, I would say M1, because despite how well delrin plays- and it does play extremely well, mind you - metal>delrin IMO
But for us to really
decide what you would like, tell us what your preferences are. Look at this thread and answer the questions. http://yoyoexpert.com/forums/index.php/topic,653.0.html
Here are the questions if you didnt look at the link:
1. What size do you prefer? (Big, small, medium, etc)
2. What shape do you prefer? (Be specific: Round Butterfly, Flat Rims, pointy shape, H-Shape)
3. What response do you prefer? (Silicone, O-Ring, Hybrid, Pad, etc)
4. Do you like to mod/maintain it?
5. Does color matter?
6. How does your style relate to the yoyo? (What kind of tricks do you like to do?)
7. What is your price range?
8. What is your skill level?