I had the side step bars installed just a week ago and I couldn't be happier. I had them installed because my girls were having problems getting in and out of the car.
The term "bar" really belies its function. The area which you step on, which occupies most of the bar, is flat and there is very little chance of slipping off it. Those areas are not "bars" at all. Pictures don't properly show the stepping areas at all.
I had the girls try out the side step bars on a Pilot at a dealer nearby and when I saw that they were happy with it, I asked if their auntie's running boards were any better (she has a Toyota 4 Runner) and they thought the side step bars were just as alright.
That's all I needed to hear and had them installed a few days after that. IMHO, it looks better than the running boards.
Also, I think it's easier to maintain in terms of keeping it clean. Around here parts, once the snow melts away in the spring, we get alot of dust and small rocks flying around all over from all the sand and salt the municipality uses during the winter and I see many running boards dirtied up.
If you can get a chance to actually see and compare the running boards and the side step bars, then I'm sure you can make a much more informed decision. Good Luck!