While I've enjoyed de Haas' books immensely, I thought that particular action was nothing to rave about. You might pose your question to the folk at forums of the ASSRA.

I went and looked at the Dakota site to see their action. The claim "the fact that 75% of all Schuetzen competition shooters choose Miller" is likely pure B.S. The Schuetzen scores I've seen posted never list a Miller, but most of the ones I see are ASSRA, and those guys prefer the older actions. I've read Dakota went bankrupt for good reasons; take care.

edit: Ok, I was wrong: I just looked at the ASSRA forums today and find a post on C Sharps triggers, and in one reply a guy mentions the Millers are common in Schuetzen.