Tell me about Magnaflows Please

[72step]

I was planning on installing some flowmasters on my truck, but there are sizing issues because of their width, and magnaflow offers different sizes on their ovals, and they are cheaper. Also I keep hearing they are a straight through design, and offer better performance. I mean I want the sound of the flows, but performance is my priority. Seeing how flows are made, it doesn't seem like they are the most efficient way of exiting the gases. I mean, I'm no scientist but getting from point A to point B is quicker in a straight line than through a maze, right??!!
What experience/advice do you all have??? Thanks