I would choose based on MQM earnings. Now, make sure that the CZ fare that you're going to purchase actually earns MQMs. You didn't specify Business or Economy. Business you'll be safe, but most lower priced CZ economy fares earn zero and the other cheaper ones earn 40%. Same if you choose 9W or MH, make sure you're actually getting an RDM earning fare class.
As for product, on these regional routes, not a huge difference if you're talking about economy.