Hi, I'm the devils advocate.
Opinions are good, so are comparisons... So long as they're informative. A critique. So take your opinion, but be sure to give reasons WHY you like/dislike something, and use comparisons to show similarities/contrasts. That is something we can learn from. Even if I may learn that I don't share the same tastes as you, I could have a bit of an understanding of a different aesthetic. Maybe even come to appreciate something I didn't like before, through knowing what about it is appealing, knowing what to listen for.
So my beef is more about lazy opinions, who don't bother with explainations and are content just to state their position. That's a buncha stinky, hot air. Pfft.