I have used one of these. Pleased with the results. No screws visible on outside surfaces.saw this nice idea . not in love with the pocket hole joint strength-wise ,but this is good
I also have a biscuit jointer that makes really beefy joints, especially in thicker wood; but it can give a slight 'kick' and leave the 2nd piece of wood very slightly proud of the 1st piece. Sandpaper is a wonderful thing ...I did use one a few times on the self build, okay for building frames but I preferred lap joints (and dancing) much stronger with epoxy glue, but mainly I could use plastic moulded corners with screws and Sika really solid joints.
16mm Radius Corner Mould Plastic – Magnum Motorhomes
magnummotorhomes.co.uk
Why don't we have the Robertson Screws in general use? Blame Ford and his meaness to not pay for the rights to Robertson in Canada.Posh git, I couldn't afford the Kreg one I got the Trend one, if they were not so bloody expensive I would have bought Robinson screws for the build, but you need so many different sizes, I bought a Screwfix kit of assorted Panheads, just as good for pocket screws. back in the 90s, we had a rep come round selling kits of square drive screws we bought loads, but all gone now. I think they might have been invented up the road from us in Shipley, never had one slip, dunno why we still have crappy Pozi drives and Phillips.