Hi Tamoo

Well, not sure about alcohol but when the wife & I have purchased toiletries at LHR the Duty Free staff have made a real fuss about anything over 100ml. They insist that Doha security will confiscate anything liquid over that limit & explained that they are worried customers will complain about being sold items which can't be taken through a stop-over airport security check. Flights going non-stop to BKK (or any other destination) aren't affected. Interestingly we've had the same problems buying Duty Free in BKK on the journey back via Doha.

We reached a compromise with the staff where they annotated any receipt with a hand written note stating that we (the customer) have been warned that our purchases were over the recommended limits. We've never had a problem but then again we've never taken alcohol sized bottles through Doha.

As for the three-class flights; QR do operate 3 class aircraft from LHR-DOH & occasionally DOH-BKK. We flew DOH-BKK C class last year on a A330-300 & there was a First class cabin in front of us. Last week we were upgraded from C to F DOH-LHR on a A330-200, the nice bit was they upgraded us in the Premium terminal before a 4 hour stop-over so we had use of the facilities. Stop-over & flight were both very nice indeed thank you!

However, to be honest the flights on a QR B777 aircraft are almost First class in their own right, a fantastic experience (awarded worlds best Business class & Business class catering 2010). I would say check the timetable carefully & if you can manage to bag B777 flights throughout save your money & stay in C (the B777 doesn't have First class).

Of course, it's all about opinion, you pays your money & takes your choice...

Hope this helps.

Cheers.