Here's what I think.

I fly MH a lot regionally and long haul in J.

The seats on the 772 that ply LAX-KUL have got angle flat seats. Though that being said, the seat pitch is really excellent. So in that sense, it's better than AA. (Excluding their 77W). There are no plans for any refurbishment for now. MH has got good service and catering on long haul.

Flying in Business on MH and crediting to MH will give you 150% instead of the usual 125% for crediting to most other carriers.

Elite bonus is only 25% for SL & Gold. 30% for Plat. But if you're going to fly MH a lot, then it's still worth something.

MH Regional is just fine, and so if you decide to fly on the short hops in Economy, only MH cheap fares will have mileage if credited to MH themselves.

Lounge in KL.