But are they any good... 
Rob
Yes they are.
Well the ones we use at work are. (We don't buy them from Cromwell's either)
Will tear through almost anything, no matter how hard or abrasive. Ideal for use use on stainless, titanium and high-carbon toolsteels.
A bit of a pain to sharpen, you need a green carbide or diamond wheel on your grinder. And a bit of patience.
They will stand an incredible amount of axial pressure when drilling, but they are brittle and will shatter or snap from any off-axis load. So on "difficult" materials they are best used in a pillar drill with the work firmly clamped.
one_rod.
