I'm not a fan of mavic road wheels, Had splits in Ksyrium rims twice.
I bought some Planet X wheels last year as they are very similar to the Alexrim wheels I use. The Planet X wheelset went straight to my wheelbuilding guru, before they were fitted to the bike because th tension was all over the place.
Not really Planet X's fault - the wheels hadn't been out of the box since they left the Chinese/Taiwanese wheel-building plant.
I think the Planet X are the faster, lighter wheels, but budget an extra £5 for truing.
Local wheelbuilder was OK with it - he knows he can't buy rim, spokes and hubs for th price of factory wheels. I think he much prefers tweaking clean new wheels, than trying to sort them out when they are dirty and pringled.