Not sure what I can bring new to the table here. i agree with a lot of the other reviews.
So I've been replacing a lot of Harley Benton pro - gold flat patch cables on my board. Why? Because they are microphonic. Don't believe me? Well just tap the black plastic cover on the rear of the connector and listen. I probably didn't need to replace them but I did anyway.
So yes I agree with others - ditch the enclosed wire cutter/stripper - just use a sharp carpet knife, Stanley, or similar. Ditch the screwdriver -sooner of later the shaft is just going to turn in the handle. Use another.
I've bought two of the kits and an extra connector pack too (great that Thomann now offers this), and have made up probably in excess of 15 patch cables (not exactly sure). All connections except one were fine first try. The flakey one I found with the multimeter straight away and corrected within 2 minutes.
The cables are incredibly quick to confection, it's fun too. I would say that key is to use a very sharp knife and to ensure that the cut is as near perpendicular to the cable as you can get. If there's any screwness to the cut just trim off a sliver of the cable to get it right. Do use a multimeter to test your cable for open or short circuits before applying it to the board.
The connectors are very low profile and are not microphonic. The cable is thin, flexible and has a very low capacitance. I think I measured something like 130 pF/meter but as it's been a while ago now please don't quote me on that. The audio transmission is certainly very transparent and I've detected no pre-buffer, high frequency loading of the signal. It's a joy to route with such cable.
Now many will say that soldered connections are more robust and reliable and I'd agree with them. I can't say how robust these mechanical connections are or will be with time. Right now they feel good. I would not chose to use this cable and solder-free connections for an instrument cable (although in a pinch it would probably do the job fine). And to be honest I don't know whether I could find a right angled solderable connector with this low a profile.
But right now there's so much right about using this kit for your own custom patch cables. The price is right and the quality feels like more than you pay for (just ignore the supplied tools). So right now, highly recommended. Should I have any future problems I'll update this review.