I have both a small-body Larrivee (OM-10) and a large-body Lowden (O32-C). I love them both, but they are very different instruments from one another. Both builders are known for a certain amount of structural innovation, particularly in the bracing. Both of mine are spruce top, rosewood back and sides, which is my personal preference for the types of music that I play.

The Larrivee has a sound that could be described as "piano-like" -- each note is clear and distinct, the response across the tonal spectrum is very even. In the six or seven years that I have owned it (I bought it new), the tone has opened up very nicely. It used to have a sound like cut glass, but now is warmer and richer sounding, while still retaining a certain "chimey" character.

The Lowden is a big guitar in every sense of the word. It's Lowden's signature body style (kind of a jumbo), with a gentle and not terribly deep cutaway. The sound is big and open, warm and rich -- it moves a lot of air, if you know what I mean (words fail me). It is a guitar unlike any other that I have ever played, and certainly a different breed than a Martin, Gibson, Taylor, or other more "conventional" American guitars.

I string both with medium gauge phosphor bronze strings (generally D'Addario EJ17's), and fingerpick and flatpick on both. They are very versatile instruments, but like all guitars you have to play to their strengths to get the best out of them. I would not consider either to be a bluegrass guitar -- if that is what you're looking for, I'd focus first on dreadnoughts, with Martin as the starting point and Gibson, Taylor, Larrivee (dreadnoughts), Collings, Bourgeois, and lots of others in the running. And as other folks have said, you need to let your own hands and ears guide you more than the opinions of others. But Larrivee and Lowden are both excellent instruments, so definitely check them out.