they deliver, you dont have to go to the hire place and back again,
and
the stuffs new not knackered.
Well I don't have a car, so would rely on delivery anyway.

Even a plain steel bit would manage 3 holes, tct is way tougher. No
problem there.

That's what I thought.

Sideways movement of drill tends to cause snagging, so I'd take it
easy
if you use a no clutch job. Keep speed down to aviod it biting you,
and
not use up a ladder.
This is the reason for buying a new drill. At =A366 I don't think It'd
be costing me much more than a hire. It has the clutch and claims to be
able to do 65mm core drilling. It must surely have less sideways
movement than my current one! A quick google search suggests other
people have successfully used similarly rated power drills for this
work.
Mark.