Probably the only set of strings that I can say had a dramatic effect on the tone of a guitar. I have experimented with different strings with every guitar I've owned, and all have some subtle effect. But the HD Elixir immediately brought a bell-like ringing tone to my rosewood/spruce GA BTO. Maybe not as warm as other strings, so it depends on what you're seeking. I find HD lights to be louder, clearer and more resonant. Maybe it's the rosewood, but the guitar still has plenty of bass, just a more pronounced ringing bass, but not as warm. I'm not saying this a bad thing. I love the tone, but I admit that I have other guitars (Martin HD-28, for example) that have that lush, warm, chordal bloom when i want that. When I want to hear a loud, clear, balanced, bell-like tone, the Taylor GA with Elixir HD lights has it. (By the way, my usual strings on that guitar were Elixir PB lights, which I loved until I tried the HDs. Still use that type on a 000-28H Martin.)