I personally do not believe that Mcycle reviews are biased towards advertisers. Bikes are, relatively, cheap enough that no editor would risk that for the meager rewards, if any. Boating magazines, that's another story. Just getting access to a 150K boat to review is tricky. Trash Bayliner and see if you ever get one again to review. But I digress.
The editor for Rider, I think, addressed this over the summer. He basically said that ALL modern bikes are good bikes. They just point out differences and that doesn't equate to the word from God on which is best. Just opinions on what people liked and didn't (as others have noted in this thread). Which is run to write about and to read.
I think Flat screen televisions are a good example people can relate to. Go to any big box store and look at the wall full of panels. NONE of them are dialed into YOUR room, accustics, etc. Yet this one looks better than that one. Doesn't mean you'll like it at home. And when you do get it home and get it tweaked out, you don't have 40 other models set against yours showing its differences. So you love it, it fits, and might recommend it to others. Same thing for bikes et al.
Short of a magazine doing an expose on a manufacturer substituting substandard parts for specified parts and/or the factual specifications, any magazine review is just another person's opinion. Fun to read and look at, that's all.
Now, tie this into a discussion of test ride before you buy (what dealers will and won't let you) and THEN it might get interesting ;-P