It's an
open secret that you can fly Malaysia Airlines' business class by paying economy-like fares through the MHUpgrade offer.
I fly MH domestic a fair bit. My success rate has been pretty high, 8 out of 10? In the last six weeks I’ve had success for flights to KCH, BKI, PEN and JHB. Usual upgrade is for 1-2 persons, but I’ve had success rate for up to 6 pax on a KUL-KCH flight.
Congratulations. You're flying business class for peanuts
A bit of strategy: I start out lowest unless it’s a flight I really need the luggage allowance/lounge access etc. whereby I’ll start a bit higher. Red zone mainly. Wait and monitor using KVS Mobile Companion Tool or Expertflyer etc. If you get a “Increase Your Chances of Being Upgraded” email from MH, you are looking good. Usually I just make a token increase and I’ll get the seats. Needless to say, you can jack up your offer if you really want a particular flight badly. I’ve never paid much more than lowest bid allowed. YMMV.
I don’t fly MH for international flights anymore so can't report much. My last flight was in February this year KUL-LHR return on their A380. This is the only flight I would consider MH for at this point in time.
So, back to the trip report. I had a business meeting with a client, the wife had some shopping to do. We used MHUpgrade and paid USD50 to get upgraded to business class with a generous 40kg allowance each.
The wife's pre-flight preparations. All empty. 
Got up before 5AM as we were taking the earliest KCH-KUL flight departing 6AM.
There were only four of us up front
Recliners for the 1h 40m flight
Bidding Borneo goodbye