As mentioned the high NIB cost, another problem is its hard to beat a Glock's repeatable trigger for use in the production class. That and the fact there are tons of aftermarket goodies for Glocks. The DA/SA trigger transition is hard to run fast, making HK's, Berettas, CZ,s etc. the minority in the production guns. Then I watched someone shoot with a DA only USP, and between the trigger and his flinch it was, well...painful. And long.