I was wondering if anyone has used these single flute carbide cutters:

http://www.ebay.co.uk/itm/5x-6mm-Car...#ht_2706wt_905

They're a lot cheaper than anything I can find in England ... but will they be any good quality?

I've chosen single flute for the obvious reason - more space to clear the swarf.

I'm intending to use them with 18mm plywood and probably aluminium. I've been using the 6mm router bits from Toolstation recently but not having much luck. It's quite a lot to spend if they turn out to be no good ... can get 19 of the 6mm carbide tipped cutters from tool-station for that price so it's only worth it if they last at least 4 times as long.