You are going to love your Dyna.
The only problem I've had in the 8 years I've had my Dyna.....once the vent tube slipped off my gas tank and it wouldn't start. That was a $0 fix, once I figured out what the problem was.
Other than that, it has always started right up at the beginning of every season.
Oh, I did have the carbs cleaned once due to some gunk from leaving gas in it during the winter. It still started and ran....it was just sputtering, so I drove it to my buddies garage and he cleaned the carb.
I store it in my garage or basement during the winter (well, it's always garaged). Point is, keeping it away from the elements helps keep the maintenance low.
Harley's have a jaded history of being unreliable....but my Dyna has been just as reliable and easy to maintain as my old sport bikes.