I find tuning the guitar down a whole tone then using a sawn off Schubb capo over the top 5 strings a great way of getting standard tuning (normal capo 2nd fret), drop D (5 string capo) or playing it open to get F & C with G & D shapes etc. My guitar is a Martin 00016GT and sounds grand with Elixir's light top, medium bottom set.
Cheers!