+1 on that.

I hope your heart isn't set on a BMW, this to me is a decision for the head. BMW will tell you their bikes are a premium product etc. It's marketing guff just like Harley will tell you their products will make you a rebel and Ducati will hint at you meeting beautiful women.

A working BMW is a perfectly good bike. What you need to ask yourself is what you'll be happy riding and what you'll do when it stops working. If you want 130 mph performance, can ride a half ton machine off road and don't mind trucking it to a dealer when it breaks the GS is maybe for you. If you can live with 80 mph performance, find 300 kg easier off road and know one end of a carb from the other there are real alternatives. I'd include KTM's in the list too.

BMW's ceased to be built better than other bikes in about 1995. Today they just have different technology and so fail in different ways. If you understand then you can fix them. More people worldwide understand KLR's etc. if you do need help.

If the badge does do it for you it's no shame to go for it. Having confidence in your machine because you feel it's up the job is probably as important as actually having reliability, your head will be set for the road not listening for impending disaster. I've had 4 BMW's and badges (the blue and white one in particular) don't do it for me anymore, but a lot of BM's have done big trips and worked out just fine. So have Urals, but I would't recomend them either.

Check out the what bike and tech threads and pick what your head says will work for you.

Edit to add: When's the trip? IMHO you want the bike on your drive 6 months before you set off and through the first set of tyres before your departure date. Best to get any bike through the learning/running in/finding out it's a lemon before you get too far in.

Enjoy whatever you get.

Andy