I have Lee Oskars in Am, Bm, C#M, Em, Gm as well as Bushman Souls voice in the same keys. I find the Lee Oskar like all Lee Oskars can be slightly bright even a little harsh if you do not hit the bends spot on. The Souls Voice have a richer tone. They are equla temperment so single note will sound great chords a little harsh.
What is it you find sounds bad , chords , all around tone?
For minor keys, the best thing to do is have a major key harp, which has
a root that is one step lower than the minor key root.
Example: Dm, C-Harp; Gm, F-Harp.
This produces a good quality sound compared to natural minor harps, or
using the relative major key harp ( Bb for the Gm).
Mac please explain some more on how playing third postion with only one available chord, rather than a NM that has two available chords in the correct key works out better.