I currently own a Starfire II and an X-170. Both were made in Westerly, RI. The SF2 was made in 1996 and the X-170 was made in 2001. Both have laminated maple bodies.
They sound markedly different. The SF2 is much brighter and acoustically louder than the X-170. The deeper body and larger lower bout of the X-170 seem to swallow the sound of the strings whereas the SF2 seems to reflect and project it. I've actually recorded the acoustic sound of the SF2 to great effect, particularly for fingerstyle pieces. As you'd expect, the amplified tone of the X-170 is much darker than the SF2 and would be more suitable for attaining a traditional jazz guitar sound. It's very rounded and rich, particularly during chord comping, but the neck pick-up doesn't jump out during solo runs. It needs a little bit of bridge pick-up (IMHO) to give it definition.
The SF2 is really more of a rock guitar, but it can do anything quite well. I love it and have played jazz on it myself. Mine seems to have a particularly fast neck, and if you roll off the tone knob, you can get a useable jazz sound. I'm sure some purists might quibble with it. For my money, the SF2 is much more versatile and its capacity to resist feedback still amazes me. If I could have only one, I'd buy the SF2.
Now if you're talking looks, I've got to give the nod to the X-170. That rolling cutaway is a lovely thing, and it's so comfortable!