Collapsible two-piece wire music stands have been around for decades, as a cheap and portable solution to traditional heavy-duty Manhasset or Wenger models. Although they can be tipped around in a small bag or packed away in a car, two piece wire stands are notoriously flimsy, with an unfortunate habit of tipping or falling over at the worst possible moments.
The K & M Deluxe, made in Germany, is a collapsible one-piece wire music stand that is designed to be sturdier than the usual two piece wire models. It also incorporates a wider music tray, which helps support thicker books often used by musicians at gigs.
I have used the K & M for the last two years. Clearly, it is the best wire music stand I have ever used. Although no wire stand is as strong, reliable, or easy to use as one with a solid back, these are a reasonable improvement over traditional wire.
My K & M does tend to stay upright even in the occasional windy conditions of outdoor rehearsals and concerts, and the one piece construction makes it not only more convenient but also sturdier than traditional wire stands.
One complaint I do have is that it can be more difficult to unpack and assemble and to collapse than a traditional wire stand. The arms mean to prevent music from blowing away or refusing to lie flat can get in the way of folding and unfolding it. When I first got my K & M, I sometimes spent a few minutes both getting it assembled and taking it down, and I do not think that this process is anywhere near as intuitive as it really should be. Its "three piece assembly" must be performed in a specific order and the directions included are confusing at best.