I don’t think there is much difference visually although obviously you could not play the V shape pre de la table. At least, not easily. However, it is easier to build than the “parallel” type. There is no reason that string breakage would be greater for one than the other.

As a builder I prefer placing the strings parallel more due to acoustics. One of the double’s charms is the sympathetic vibrations which are greater if the strings do not converge at the SB. One must make the SB about 4 cm wider too, which means more vibrating surface. It also just seems more natural to my hands but I know some excellent doubles player who like the V shape better.

Just my take: Stoney End was the first of two who made doubles so they have certainly been around a while. If the question is cost Stoney End’s are less than the Rees’. OTOH Rees’ sound better IMO. Some like the Dusty Strings model of course.