Although I do most of my own maintenance, and have the diagnostic capabilities required for the vehicles I own, I have an excellent relationship with my local Suzuki dealer and trust them implicitly - it's part of the reason I continue to buy Suzuki.
I've had several problem issues with dealerships in the past.
Nissan, Suzuki Motorcycles and Honda motorcycles.
Nissan: they charge TOO MUCH money for any piece you buy from them.
Suzuki motorcycles: 3 times I've needed a spare part, and they ask me to give money in advance and wait 3-6 weeks for arrival. I can get the stuff from amazon or other places in 4 days from the US.
My brother's bike went in once for periodic maintenance and they changed the oil WITHOUT removing the skid plate. The oil drain and the oil filter can not be reached this way.
Honda: this friend of mine was charged for a full motorcycle check and lubrication. The clutch cable was sprinkled with WD40 on the lever and near the end of the cable. The rest of the cable was completely dry.
These have been my stories so far. That's why I also prefer doing my own work, or pay to my trusted mechanic friend when I feel the work requires skills above my capabilities.