i had an r1100r for 8 months and an r1100s for 6 months, both very good road bikes, but very different to the bird. (only changed the s because the blackbird is my dream bike and one came up at an awesome price) are you looking at the r series or k?
having only experienced boxertwin engine i cannot talk with any personal experience about k series (though a mate said he loved the k1200s - but not at the price). awesome torque on r series - pulls from nowhere, hardly ever have to use the brakes cos there's so much engine braking (that was a shock for the first few miles on the blackbird coming up to tight corners!). don't worry about what people say about the indicators, you get used to it after a week or so, and it is no problem, despite what all the mags say. also don't worry about ground clearance with cylinder heads - get some magnesium covers and it looks fab when you finally get them down (though it takes some doing!). plenty fast enough for the road, and 6000 miles service intervals make sense. paralever suspension, although heavy, is a tremendous tool to have on your side - mid corner braking for the those whoops s*!t moments!my advice, for what it counts, would be to take one out for at least 3 or 4 hours if you haven't ridden one before, because although they are great bikes, they are so different to anything else. most bm dealers are pretty good about lending bikes out for longer test rides.
hope that helps.