Thanks everyone for your replies. In the end we decided to go for a direct(ish) flight, just an hour and a half in KL.
We now don't know whether this will be a holiday or the real thing and decided we might be a bit too stressed to enjoy a stopover if it's for real! Will do it in the future instead.

Thanks again everyone!

Loopy

Which is preferably, get the journey over and done with without too long a break in the middle for re-fuel etc. and take 2 days to get over jet lag or stop over for 2./3 days in a new country and sample the delight plus catch up on a good sleep and enjoy australia from the minute you land. Having done both I opt for the second every time (three to be exact) It is worht a little more money it is certainly less stress.

That's a shame you are going to miss out on a taste of Asia, it is such a magnificent place. And you would never want to eat in another indian or chinese restaurant in UK once you have tasted the real thing.

have been to KL numerous times. Its a great place. True it is a bit out of the way from the airport to the hotels. We are going to Australia next month with a stop over in KL but will only be there for 2 hrs waiting for our connection. I would love to stay in KL for a while but unfortuntely time is not on our side. I personally hated Bangkok. Its noises, sweaty and full of polution - but hey everyone to their own.