I've been pondering this question as I've calculated based on my travel plans next year, I'll be at around 800 with a few months to spare before the end of my membership cycle. From all the research I've done, I don't feel it will be any added value for me to go on a MR just to try and hit diamond.
- I don't fly that often, mostly just long-haul J every 3-4 months with a few short-med flights here and there. Therefore the chances of me being op-ed up will be slim, based on the fact that I don't travel that much compared to others. I've thought about trying to book PEY on my long haul flights and testing my luck, however I've realized I NEED to guarentee my comfort on a 15 hour flight.
- Other perks such dedicated telephone line, or better availability for seat redemptions won't really matter based on my current flight patterns.
- I don't value F lounge access that highly. CX J lounges are perfectly fine for me and to be honest, I usually go to the airport as late as possible and just pop in for a bowl of dan dan noodles.

As cool as it would be to actually hit Diamond and knowing that next year will probably be one of my best chances, it's just not worth it nor neccessary for me. The 1000 mid tier benefit however... not sure if it would be worth it to try and get that if I'm close.