I am a happy Response 2.5 owner, however, many people who've heard both seem to agree that the D25 is better. From what I remember of the discussions it seems the D25 has better bass extension and weight, a slightly more neutral presentation and is easier to position for good imaging and sound.
However, when I was deciding between the two what swayed me in the direction of the 2.5 was the slightly warmer reputation of the 2.5 and the great bargain used prices available. I found a beautiful pair in yew wood that I'm enjoying.
You should run a search in the forums as this has been discussed and will give you a more in depth understanding of the differences between them.
Good luck!
However, when I was deciding between the two what swayed me in the direction of the 2.5 was the slightly warmer reputation of the 2.5 and the great bargain used prices available. I found a beautiful pair in yew wood that I'm enjoying.
You should run a search in the forums as this has been discussed and will give you a more in depth understanding of the differences between them.
Good luck!