Don't know about the De Capo's, but I currently use the Minimethod with a pair of Tones. There is a Minimethod up on Audiogon right now for a pretty good price, though if you want to get a brand new one for a price similar to that one I believe Zu will soon be doing a holiday sale, and last year they were selling the Minimethods for $1000 I believe. For my purposes, with the Tones, it adds a nicely defined lower octave with good impact and resolution (not the deepest extension though).