you don't HAVE to fill the grain on swamp ash...

I use tung oil on it, and it comes out nice with good gloss, absolutely slick feel...its not a plasticky mirror-smooth finish, but if you like the look of s ash, a tung oil/varnish blend can work well, if you put enough coats on. I too would recommend swamp ash as a tone wood. Pretty nice I think.

The person thinking the L6S was a jazz guitar was probably confused with the L5...two VERY different guitars. I too was initially confused.