(Review based on test ride) I was looking forward to this bike enormously. The quirky looks of the bigger GS without its enormous bulk seemed appealing for me at 5'10.
Initially I was really impressed, the motor pulls well from low down and only runs out of guts and feels a little vibey at fast motorway speeds - perhaps 6th could be longer. It was quickly evident that its native territory was back roads where the power was plenty and punchy, overtaking and cruising with ease. Gearchanges and braking faultless. After the initial "its very different" transition from my usual rice-rocket, I discovered quickly that its so rideable. You can flick it through bends with a heave on the wide bars and you can see over all the cars and hedges... It gives you the impression that you're in control of the bike - and perhaps even the road.
However, the little screen offers scant motorway protection and after only about 15 miles in the close wakes of swathes of weekend travellers I was aching to get away from the buffet and finger numbing vibrations. A desire I haven't experienced since the 100cc commuter I left behind in my teens. This was disappointing because on A-roads at similar speeds the bike was entirely composed and the buffet much reduced.
Anyway, as soon as I was back on the A and B roads, the GS was happy again. Soaking up the ripples of the poor road surface and whipping along country lanes.
Its a long way down though - stopping at junctions I found my leg sometimes wafting about helplessly rather than planted on the tarmac...but some careful planning when you stop sorts that out. I imagine the health and safety warning stickers on the packing crate read 'Not recommended for use with less than a 29" inside leg'. An optional lower seat is available, which brings us conveniently on to the torturous device that BMW have applied for your seating enjoyment. A fair old slope on the saddle ensures that your buttocks are inexorably tugged towards your shoulder blades unless you sit at the front of the seat, where the curve up to the tank hoists your uhm, nether regions, forcibly upwards and outwards. Neither solution was tolerable for very long. Half an hour at a time was about all I was prepared to endure with frequent standing-on-the-pegs intermissions. Perhaps if you're several stone heavier than me (11st / 70kg) you might flatten the angled seat with the assistance of gravity. I enquired with the dealer whether this issue could be fixed with the suspension settings but he didn't seem hopeful. So, all in all. Great looking (confirmed by child and father at crossing), fun torquey performance (unless you want warp speed), seemed good economy maybe 40-50mpg from what I could tell. But not a friendly saddle. The BMW switchgear is largely OK, with a dash of bizarre. Not sure why they persist with 3 controls for the indicators. Very odd.
My recommendation: Ride it for more than 30 mins before you buy it. If you find it comfy, I reckon you'll love it. Otherwise you won't want to spend days on it. Loaded up with touring gear, it might be a different story... As for me, I'll be testing the 1200 next. I spied a flatter saddle there. I truly wanted to love the 800GS, but it definitely wasn't for me.