Open tunings are fun and tricky. If you can find enough songs to go along with each other in the same tuning, then it's good. Like tonight in Drop D, I played 3 Shawn Colvin songs, Set the Prairie On Fire, Shotgun Down the Avalance, and Kill The Messenger. Just change the capo..... if you want to be in her recorded tuning. But I currently have 6 guitars, and the reason for that is I want to play songs in MORE than Drop D..... and to do that, I either spend TONS of time tuning and retuning, or.... I have all the guitars in tunings that I like and just switch guitars. Your strings last longer then, too! Not one guitar here is in the same tuning. So depending on how hard it is to set the partial capo guitars settings, it could save you some tuning time.
I can't see myself buying one, but it's a cool technology. :encouragement:
p.s. - trouble with intonation, and open tunings go hand in hand. Especially, when you use a capo! So if it can help that issue..... it may be useful. Again, depending on how difficult it is to put those little individual capos on and adjust them.