slack-key tunings

I mostly keep my guitar in standard E or drop D, but I also invented my own slack-key tuning where I tune the bottom string down a semitone and the fifth string up a semitone. ie 6 = Eb, 5 = Bb. That's the tuning that Vanya's Lament was composed in, and It Might As Well Be Spring also used that tuning. I eventually figured out how to play in Eb efficiently in standard tuning, but this was another solution that I had. I also use that 6 = Db, 5 = Ab that Dyens used as a fun thing to mess around with at home. - My brother plays in an open D tuning (like most folk/traditional guitarists).