Jbspeak,
I haven't heard the D15's, but I did hear the D25's at a dealer and I was amazed that a speaker with only a medium sized mid/bass driver could throw out a sound as deep as they do. Typical ProAc sound, smooth/sweet & not tippy in the upper regions. A lot of presense. They were demoed using an ARC VT100 & a LS25 MkII.
We played some rock/pop & jazz and it all sounded very good. In fact we played some dynamic percusion pieces and I felt the thump on my chest. I thought that only larger speakers could accomplish that.
The speaker has a large port facing downward. I have to wonder how the sound would change on differnt floor materials.
Anyhow, I too am mulling over buying them - I wish they cost just a bit less.
Steve