The 3-way Klipsch sound is hard to describe. Mind you I've never owned Fortes, but, I do own Choruses. Choruses are the same configuration except they use a 15" woofer.
They're very detailed, dynamic, and dare I say, bright. They're enjoyable at low volumes unlike many speakers that I've experimented with. They reveal subtleties that otherwise remain buried below the surface provided that your source(s) are up to the task. They aren't accurate, they're not a "monitor", some people detest the Klipsch sound. Personally, if I could sum them up in a word, it'd be fun. They are a fun sounding speaker. They're very hard to walk away from if their character is indeed one that suits your listening taste.
It may be worth pointing out that the Forte II uses a Tactrix midrange horn as opposed to an exponential midrange horn as is used by the Forte I. Generally speaking, the Tactrix horn produces somewhat of a smoother presentation and a bit less "twang" or "honk" than an exponential horn. If you like that gritty sharpness in your music, you may want to opt for an older set that use exponential horns. For example, the opening guitar rift in War Pigs on my exponential horns is just mind blowing. When I run the same song through Tactrix horns on my KG's, it sounds a bit more tame and less raw. Just some food for thought.
Either way, if you can get these for a reasonable price, you most likely won't be disappointed.