JMO: I took my 2009 RSV Hannigan to Southern Honda Powersports to have the differential fluid changed. Should be about a 30 minute job. Took almost 5 hours because the mechanic could not find the drainage bolt. He actually separated the halfs to get it done and that was (Honest!!) after I explained and told him how to do it. Great sales staff, great selection but I've had one RSV trike and one GL1800 Trike problem that keeps me from using their mechanics. I finally took the GL1800 MotorTrike to Honda of Knoxville, who recognized the problem, fixed it and it's been trouble free for near three years.
Also JFI, I use Luke Ritter, owner/mechanic of Kustom Bike Worx of Jamestown, TN. He has been my go to mechanic for a couple of years. Excellent work, rates are very competitive. Kustom Bike Worx