You need an option for neither or both. I use both just to keep my body guessing. I have developed more strength and power using the Strait Bar but the supporting muscles do not get enough engagement when I focus only on that. I notice that various parts of my upper body start to lag a bit when I focus only on the strait bar. As a result I switch my sets, reps, and reutines fairly consistantly. I try not to do the same movement for three weeks or more.
In this way I am alway changing and forcing my body to keep up with the pace and switch up. So I guess my answer is that I perfer both for different reasons. My body just likes it better that way.