So far I am the rock drills come through any kind of stone (I live in an old building with different masonry). The wood borers were particularly convincing, even after prolonged use (Have a bunk bed made of solid wood) still sharp.
The metal drills and the countersunk head I can not say anything, so far I have not yet used this!
The Verlängerungsbits are not particularly high and eggs a bit in cordless screwdrivers and in the drill, as well as an isolated incident by defective production can be.
I use the bits with the "Mannesmann 12538 electronic percussion drill (1020 watt)" and get along well with this combination.
All in all for the part-time handyman a good collection of bits and drills at a fair price. Buy recommendation!