Reiska said:
Or is it purely a drilling thing like cheap 'hammer drills' i.e. not real SDS hammer drills and should it be classified as a gimmick?
It is not a gimmick, I don't understand why you would even use that word. It is a very useful option. A hammer option on a regular drill is a very normal thing to see, and it is meant for drilling holes into stone walls that are harder than a normal brick, like for instance real stone like marble or granite, or for concrete walls. And sometimes you'll even find bricks that are as hard as a rock and impossible to drill into with a non-hammer drill.
Of course they are not as powerfull as true SDS drills, which often have a whole different "pneumatic" mechanism. The standard hammer drill is simply meant for the smaller jobs in and around the house, mostly for drilling holes for plugs up to 8 or 10 mm. Like when you need to hang a painting or a radiator to the wall.
I have had to use the hammer option on my 220v drill many times in the past, only way to get it done. For harder stone materials, simply rotating and relying on the cutting action of the bit is not enough. Hence the hammer action, it hammers the drill bit forward, crushing the stone instead of cutting. Makes all the difference.
The PDC is meant to be a cordless vesion of that. I have drilled into concrete without any problem with it with a 10 mm bit. And as was said above, the PDC is not an impact driver. Not meant for the thougher screwing jobs. But nevertheless, the PDC has such power and such a high speed, you'll find it can do a lot of screwing anyway.
