Its second hand info from reading reviews, but I've read a lot about poor low speed fueling, poor front brake feel, etc. I don't really want to drop another grand for a Coober unit and new brake pads, I guess I won't really know unless I get one and live with it for a while.
I know 5 people who own 790s.
1 has put new pads in for £40 and massively improves the brakes, I'll likely do the same.
Fuelling, i just don't get it, it's WAY smoother at the same rpm/speeds than a 690 ever was.
Handling, hell, I've watched Vids of Fagan (Used to race in BSB) who's a million times quicker then me lapping tracks on it. I've ridden my bike on track (well, not mine, but a 790) and been with mates who can lap 5-10s a lap quicker than i ever will, none complained about the handling... If you can out-ride a 790 suspension, you're a VERY skilled rider. The 790 is 100% more stable at speed/corners than my 690s ever were.
I know i'm biased, but i loved my 690 too, the simple fact is, i can't think of one thing a 690 does better than a 790 i'm afraid.