The holes I drilled, went without problems (even with hard tiles) were all very nice and with a clean edge - nothing is broken. BUT: Unfortunately, the drill broke after 6 holes from underneath the cutting head. Since I had a second drill at hand, I could continue my work. The second drill keeps so far, however, was not much in use. Personally, I would buy the drill again, even if I knew that he holds by only 6 holes, since my trouble drilling these few holes is worth the money anyway.
CONCLUSION: A handyman who wants to drill one or the other hole in tile, gets with this drill is a good tool at a fair price. Professionals and all those who have countless holes in tiles in front of him, should take up another drill or equal to order more than one piece, since the quality of a "continuous operation" is not apparently enough.