Proac 2.5 vs Vandersteen 2Ce

vandersteen no contest, it floored me.

Proac is a fine speaker but for all the qualities you cite -- "warmer, smoother, and generally more musical" -- the nod has to go to the Vandersteens. They are not the last word in detail or soundstaging, but they are, well, warm, smooth, and musical!

Interesting observations. Just curious about the amplification used for comparison with both these speakers?

I have heard the Vandersteen 2CE Signatures in a showroom with ARC tube amplification. I found them to emphasize the lower midrange at the expense of the higher frequencies. They sounded smooth, but I didn't care for the tonal balance. I own a pair of DIY Proac 2.5's and really love their bass and midrange response, well extended but not at all thick. They manage to sound rich, but not at the expense of the high frequencies. I love playing cello and viola d'gamba recordings through them. They mate very well with my ARC tube electronics. They also have a relatively small footprint. I urge you to audition both.