We've flown this one a few times, it's not always almost empty.
The lounge at KUL, however is often more than 100% full. ie. you'll not get a single vacant seat.
As someone pointed out, above, its a great deal if you're carrying luggage, Mrs Werldporks and I both have Star Alliance Gold memberships, (thanks for the status match CO !!) and we can carry a ludicrous amount of baggage on that trip.