They are a couple of miserable types on first impression. Hell, they can be miserable gits on second impression too, but they know their stuff and hardly ever even have to look at the PC to know if they have it and many of them they have.
I had one of the Thetford septics follow me over there Saturday for some axle seals, both the brothers had the time to stand around and BS for a good half hour. Andrew showed us his "new" XJ and the Comanche he's working on, Julien patiently explained to the septic that changing the seals on a TJ D44 will f up the bearings, so he will need new ones anyway. Didn't force it, didn't get pissy when the guy um'ed and ah'ed about buying the extra stuff.
IMO, they are top blokes, just look past the grumpy dastard exteriors. If you ever get the chance ask Andrew for a tour. Great stuff hidden round the farm.