I love mine. Definitely the most fun bike I've ever owned. Tunnel UK is on the money request the servicing etc but once you get the hang of getting the tanks and plastics off things get easier. Big service involves clearanges which means getting the cams out if they need adjusting. I did mine last year, took my time and didn't have any problems. Make sure the carbs are balanced, made a big difference to mine.
Things that commonly go wrong are the fuel pump (I replaced mine with a solid state conversion) and the big one is the water pump shaft seal which is prone to failure. Symptoms include a flickering oil light on tick over. A lot of bikes will have had this fixed I guess.
Other than that it's a brilliant piece of kit, handles so well and NEVER fails to make me smile when I'm out on it.
Buy one.