M2M is "member to member" - i.e. the sales section, where members buy and sell watches from/to each other. You will need to have written a suitable number of "quality" posts in order to buy or sell. Also consider becoming a supporter if the rep hobby bug really starts to bite.
You're in danger of triggering a lot of members, by daring to ask the question, "Who makes the best Sub"...

This is where you need to start doing your own research - check out the Rolex section of the forum for all the info you could possibly need in order to make an informed choice. There's a LOT of posts about the ceramic Subs, particularly the Hulk. Look out for VSF, ZZF (now "Clean Factory"), and Noob.