Just a quick report back on the top up card.

Did a £500 topup and it posted today on Amex quite happily as a normal transaction, miles are through yet but should appear as normal I guess....

Interesting thing to note is that perhaps the £200 daily withdrawal limit on the card is not so strict. I was able to get £490 in 3 withdrawals of £200, £200 and a £90. Next time I'll try in one go and see what happens...

But indeed this does look a good way of getting mileage at a penny a mile or there or thereabouts...

-mrploddy