I bought my bike 6 months old nearly 2 years ago. It had already got 14k on the clock as it had been used by a serious rider who did road trips to europe but had been very well looked after. I chose it for a number of reasons: I was sick of sportsbikes and wanted something different, I'm tall and so is the GS, I wanted a bike I could ride all year round without complaint, with great weather protection, could cope with traffic, inner city riding, A-roads and motorways in equal measure and wouldn't fall apart in a few months.
In short it's been brilliant. Fabulous handling, grunty motor, very practical, you can see for miles and it's got enormous road presence so you don't get bullied by the traffic.
The reliability has been superb and the fit and finish is remarkable. I've ridden through 2 salt encrusted winters and not really washed it much and it still comes up gleaming after a jet-wash. Shaft drive is a godsend - no fiddling around, chain lube or tensioning.
Heated grips are great, BMW recovery are great (I ran out of petrol!!), fuel economy is around 45mpg, it's unbelievably practical and I'm struggling to find a reason to not buy another one.
The downsides? It's bloody heavy stationary or paddling out of a parking spot (not noticeable on the move), the battery is a bit weak (replaced under warranty) and the gearbox is a bag of spanners but you get used to it. If you're a shortie you won't like it so much either. Overall, fabulous bike.