Whoever mentioned these a while back:

http://www.screwfix.com/prods/95958/...l-Bit-Set-4-Pc

I got the 7 piece set from Axminster. Tried them today.

So far I am *deeply* impressed. They really do drill proper brick at 10mm
with no hammer and surprisingly little effort. They seem to be quite good
at not wandering too (important as I was setting out battens that needed to
be precisely mounted).

And they drill celcon crap-blocks cleanly enough too.

I'll be more impressed if they last more than a week - but time will tell...