Domromer! I am doing a very similar thing..coming off of a super reliable M109R. 30,000 miles of pure bliss with all the required maintenance stuff any bike will need. If I took everything seriously on the M109R website I would never had the pleasure of owning such a great machine.
Keep it simple, they're all just machines that turn our fancy. I do agree buying used you should do some homework but being a previous bike owner I'll assume your no rookie.
I just bought sight unseen a Triple Black GSA with 640 some odd miles on her and cannot wait for winter to end.
If you ever have been to a BMW demo day and had a GS or Adventure out for a blast then you will know why they are sought after so much.