Pros: Good amount of bass
Cons: Gets sweaty after 10 minutes, no sparkle in the sound
They are about as good as my Koss KSC75 but with a bit more bass. Now I quite like the Koss, so it is no bad thing being as good as those. But the Koss are £12 earphones, so the price of the Monoprice is about right for what you get.
In my opinion, the people who hype these up on forums are too impressed by the low price and have not made proper comparisons to decent headphones. Then there are those who have nothing better to do than to make wild claims about the sound quality of the headphones they own. I would be very careful about believing these people and all of their hype. I was taken in, but I wish I had read reviews from more experienced and trustworthy people who recommend the Creative Aurvana Live in this price range. Those are the headphones i would choose if you are looking to spend little money. The CAL have a similar sound to the Monoprice, but when you compare the two you notice how much more energy and sparkle the CAL have. This extra energy makes a huge difference. They make the Monoprice seem a bit dull and boring. I may even get rid of the Grados now that I've heard how good the CAL sound.
Final negative for me is that the Monoprice are uncomfortable thanks to the fake leather pads that made me sweat after about 10 minutes.