"I purchased this set the other day in aid of drilling through floor joists for a rewire!
I had an old set of spade bits of which were not doing the job well at all as some were blunt and some were bent through misuse. I went to the closest Screwfix branch and picked this set up as it seemed pretty good value for money and provided many different sized bits and lengths.
Upon opening the set I could see that the auger bits were exceptionally sharp, (even to the point that running your finger down the cutting edge could potentially cut you). First impressions showed that the case that is supplied is not great quality, but to be fair that's not really much of a problem as the price for such a great looking set was so cheap!
Upon the first use, I selected the 22x200 bit to drill through the joist (at a slight angle) to my surprise the bit struggled at first but I realised my Dewalt 3 speed Combi was on the fastest setting. I switched the Speed selection to 1 and just let the auger do all of the work. It literally pulled itself through the wood with little to no effort until it reached the last bit of the joist to which I gave a little nudge to help it through.
I have used this set to also drill through a 4'x4' piece of timber (again with it pulling itself through with no effort at all!)
Reliability is at 4 as I have only just used purchased them and I can see that they will get blunt after some use
I would reccomend that you try and drill straight as the tip struggles to catch the wood and pull itself through"