I think we all have different likes and dislikes, so there won't be a one size fits all answer to this. I do not like the nerf bar type. The reason being is it is to easy for your foot to slip off, others may disagree with that statement, but I've had a couple nasty slips getting into customer trucks with those things.
I like old fashion running boards because there is more room for me to put my feet while trying to maneuver my body into a truck.
Now what I have are the cheap steps. Here's a decent picture of what I'm talking about.
You must be registered for see images attach
I put those on because I needed something affordable and quick, back when I first got the truck. The are ok. Installation is simple, but it took a little bit (when getting into drive) to get down how to put my left foot on the step and swing my body in without twisting my knee, which is easer for me than most due to bad joints.
Anyhow now that I'm use to them I'd do the steps again, but one day would like a set of old school running boards.