[psyco1]

I've got the 125/senn pad and it's a great rock phone, and heard the 225 a long time ago. I was wondering from those that have heard the two side by side what the sonic differences are and if it's worth the extra money to go to the 225.

 

[Chefguru]

It's mostly the soundstage. It's like the differance between a Rs-1 and Rs-2. IMO it's not worth upgrading to, your better off going with a RS model if you want to upgrade.

 

[Spent&Bent]

I have heard both, I liked the 225 a lot, it sounded more relaxed and bass seemed more prominent, in a groovy kind of way.

Since it's a relatively slight change in sound I suggest you try the 225 again, if possible switching blind with 125 before buying.

IMHO it's worth it though, if the more agressive sonics of the 125 are getting a bit too much for your taste.
Overall you get a more refined sound, yet the cans get wild like the 125 when needed.
So if you can afford it, go for it, but again it's all IMHO,in the end it's your ears and money.......