I'm with Martin and Grab on this topic, for the most part. A partial capo does not really give you many of the advantages of an open tuning, because the interval relationships are a big part of what makes open tunings so special You can set up a partial capo to simulate a DADGAD-type tuning, for example, but it isn't really DADGAD, and most of what makes that tuning so magical is lost with this sort of simulation.

However, every time I start to think I know the "best" way to play guitar, someone comes along and blows me away by breaking all the rules, and knocking the air out of all my preconceptions. People do amazing things with guitars, whether or not I think that what they're doing makes sense.