Only downside to upgrading to buiss is it will be difficult to revert to econ as previously stated. I used to fly 3 times per year direct with Thai from London, after upgrading using my miles a couple of years ago i now find it impossible to fly long haul in econ. I have now cut out 1 trip per year and take 2 longer trips. It really is worth it. When i used econ it took me 3 days to get over jetlag and acing legs. Thai buiss is like a bed. I eat a 1st class meal 1 hour in, a few drinks, pop a sleeping tab and usually have to be woken for landing.. It really takes the pain out of the 11.5 hour flight and i arrive so fresh so as far as im concerned it gives me an extra 3 days.. I actually look forward to the flight now rather than dread it.. you are taking the correct option in my opinion.. Cheers