i don't mind the manufacturers logos as that's the branding identification and with that is free marketing, but the logo should not take way from the strength of the product.
But in saying this, i don't like the laser/plasma cut logos that are into rocker guards and bumpers. i find that those are the ones that i have to think about after i get or don't, as the cut out is just another place to try and seal out as the water and such can get behind and cause corrosion, like a boxed section of a slider or bumper and just lets the mud, snow or water in with no good way out.
On frame rails on our jeeps up here, if you don't get it undercoated every year you will see the first rust forming on your frame is at the cutouts in our frames, why i don't know, less paint buildup or the edges are first place the mud and snow stick to?
So if i'm looking at a manufacturer that i want and it has a large open logo, it's there logo, no problem, but it's up to me if i want to modify it to either cover it up, block it from behind to keep it and help keep stuff out or in the end not buy it.
that's the great thing about our sport, it has more then one player.