Pros: Super clear sound
Cons: Long wire, double sided cords, very uncomfortable!
I owned Grado SR80i's in the past and kept reading that the SR225i's were better, so I went to exchange my SR80i's for the SR225i's. And they were right, these were better! Everything that the SR80i's had, the SR225i's did better! The sound was even clearer, although bass seem to stay to the same. To compensate for this, I used an EQ.
Now the cons for these cans are the same for the SR80i's. The design is the same, except now there is a metal grill instead of the plastic that is found on the SR80i. The wire length is pretty much the same, except the SR225i's might be a little longer since you have to use a 1/4 to 1/8 adapter (The SR225i has a 1/4 jack). The wire might be a little thicker than the SR80i's, I might be wrong, but the difference isn't noticeable.
Now the worst thing about these headphones are the pads. The SR80i's utilize the comfy pads, the SR225i's have the "bowl" pads. After a short period of listening, your ears will be in utter pain from the exposed speaker (In the center of the pads). I constantly have to adjust the headphones or take breaks, because my ears kept pressing against this hard surface. I haven't done so yet, but I may buy separate comfy pads and switch them out and do the "quarter mod". I can always switch between the two.
Although, these are very uncomfortable, I would highly recommend these headphones, because they sound suuperb. These are considered to be the "sweet spot" of the Prestige series. To compensate for the comfort, I suggest either getting comfys separately or Sennheiser 414 pads, like others have mentioned.