I'm with Scott on that linkage, threaded rod is so brittle too, one slight bend and its on its way.
Never seen the Diamond close enough to understand the servo issues but Oli is the master when it comes to linkage calculations and design, a shame the 'standard' hardware is not quite up with the rest of the kit which looks to be superb.
For those who have not come across these guys yet - some well designed and fantastic clevis/horn products for all rc planes, Y ended servo arms so the ball clevis is not subject to a twisting loading, they also do a matching horn range to match up (only issue is the site is in German only!)
http://www.gabriel-stahlformenbau.de...rvohebel-25-55
marcs