Straight through glass pack designed mufflers!

Is this kind of muffler better than a straight pipe ?? i'm afraid if i take my straight pipe off and put this muffler on it will take that hollow sound of a v8 out and muffle it? it's a 3.8L . I was also thinking of just putting on one of those hollow Boom Tubes where the muffler was, like a 3 or 4 incher, what do you think of that?. Also does a straight through glass pack kind of muffler increase pressure, helping force exhaust gases out increasing horsepower?

Opinions would be apreciated!! thanx dudes !