I love 670. I've been brewing with it a lot lately. It's often on sale at my LHBS as no one buys it, so I can pick it up for $1. I've made several different recipes with it. One can be found here. Another one I did was a French beire de garde based recipe. I didn't really like that one all that much, but several strangers who had it loved it, so maybe it just wasn't my thing. I plan to do a lot more experimenting with it.
I said this in another thread recently: I've done it as short as 2 months and as long as 6 months, all in the primary fermenter. After a month it still tastes fairly saisony, but there is ever so slight funk in the nose, sort of foreshadowing what's ahead. Between month one and two the brett modestly starts to make itself known. Funk flavor starts to catch up with aroma. By month 6 the brett has taken over the flavor and aroma with some moderate residual spice from the Sacch strain left over as well as some decent bitterness still there. Clarity stays cloudy for about a month, then it becomes crystal clear overnight without any sort of fining agents. I'd love to take it longer, but I get so thirsty.