Well done, xb12x, you beat me to it. Thanks to my trusty R1100R being stuck at the dealer's while they order up some parts, I've found myself with a demo F800ST for a few days to get around on. I was going to write up a little review and post some pictures, but like I say, you've beaten me to it.
Anyway, what's it like? Well, very light, very neutral in its handling, very modern and together, but I don't think it's much different from an SV in that respect. The engine has plenty of top-end go, with a nice kick in the pants at about 5000 where it gets going, but it also has plenty of torque in the basement, too, which is rarer these days. You can drive it around in top (there are six gears) with two and half on the tacho and forty on the speedo without any problems at all, which is nice for trickling through traffic. You can also drive it at a hundred without any drama in the corners, and without the windblast taking your head off. The overall engine feel is strangely elastic - it feels like you're being propelled by a giant rubber band, somehow! It does, however, make a fair bit of dry rustling and 'shuff'-ing noises on the over-run, but I think many modern bikes do that. My own daily rides are somewhat more antiquated and make more mechanical noise anyway, so I'm not really the one to ask. The ergos are very good for me - I'm 6'3", 200 lbs, 35" inseam - but the mirrors only give me a view of my elbows, which is annoying and unexpected for a BMW. I think it's because the ST's bars are higher. If I sit on it and lower my hands to where they would be on the F800S the view of my elbows disappears. Funnily enough, in a reader's poll on a French website, everyone with an F800ST complained about the mirrors, and nobody with the S did, so I think I'm probably on the right track here.
Okay, so far, so normal. What's the big attraction, apart from the badge? This. There's a trip computer on this bike, same as you have in your car. Mileage, average speed, average fuel consumption, etc. And here's the point - this bike averages 70 to the gallon at 70-80 mph. Drive it with some enthusiasm, get the speeds up to 90 or 100 ( I'm not saying where!) for fifteen minutes or so, and the average drops to about 68. Drive at 50, stick to the posted limits, and it soars above 80. I have never, ever, met a bike like it for the way it sips fuel. The 22 owners who responded to the French website all tell the same story, incidentally. My R1100R produces 80+ bhp, gets 50+ mpg at 80 mph, but this produces the same power, weighs 60lb less ( and you can feel it), averages the same speed, and uses 40-50% less fuel. It is, quite simply, the next generation. In the US, where both fuel and bikes are cheap ( yes they are, don't get me started), I can see that you won't get excited about this, but in Europe this bike is priced like a Japanese middleweight twin, an SV or suchlike - or an 883 Sportster, stone stock and basic - and our gas costs 8 bucks a gallon. This thing is going to sell by the shedload. Finally, the guy at the dealer said that he's never going to get rich selling them, because they have been designed to take only one hour of shop time per year to service. Cheap to buy, cheap to run, cheap to service, lasts a decade, solid resale values, and that badge: what's not to like? Performance isn't all in the quarter-mile times, you know.