I can't speak for that crimper but I have used similar ones that worked very well once you learn the technique. Not all crimp connectors and tools are created equal and some connector / tool combinations just won't work well. What goes wrong with your connections? Do the tabs fail to fold over evenly or not at all? Does this crimper do the connection and insulation at the same time? I have had best luck with tools that do the two stages of the crimp separately. I use to do these connections a lot in my work and went through quite a few tools before I found one that I really liked ..... and it was the cheapest one I found at the time. Some years ago though so any model or brand info would be out of date.