Thanks everyone. I had a gut feeling that this would be OK but wanted to check first as there is a wealth of experience here. The feedback on Skytrax was fairly good too but I don't rely on them too much.
From what I can gather, the Premium Terminal is only dry during Ramadan, but it's a bit of a moot point as we'll be there c4.30am to 8am local, so I think a hot shower and some brekkie (OK perhaps washed down with a cheeky glass of fizz) will be the order of the day.
I did have a look at MH, but I couldn't find anything better than IDR22.5m = GBP1600. Mid-week isn't an option for us as we need to leave Bali on a Friday or Saturday. Sunday would also work (just).
There are a whole raft of other options but Qatar came out very well priced so seemed to strike the right VFM/Quality Experience balance. If I could ever figure out how to post photos I'd do a Trip report for you.
Thanks again