I agree - I drilled two holes with a regular drill before the bit that
came with my Tapcons was dull and warped. Switching to my
hammerdrill, and a new bit, I drilled over 50 holes before the bit
needed replacing. However, that was the easy part --- driving the
Tapcons was not simple even with pre-drilled holes. Many got stuck
prior to being fully seated, and once the driving process stops, I
could NOT "finish" driving them - they would snap off. Therefore if
they did stop prior to being fully seated, I actually drove them in
the rest of the way (usually less than .5") with a 3lb sledge, which
worked, but if not careful they will bend or break. An alternative to
consider is to drill a 3/8 inch hole (I used the same bit as for the
tapcons), then put in a piece of copper wire to the top of the hold (I
used 12/2 romex unsheathed), then drive a 16d nail into the hole.
Much easier, less expensive than tapcons, and holds like you wouldnt
believe.