Acapella vs. Avantgarde

I currently run a Cary CD-306, Cary SLP-05 preamp, and Cary 805AE monoblocks with a pair of ProAc D38's (see system). The combination is sweet and involving, but the combo just does not boogie when asked to play a large orchestral piece, by Mahler/Wagner/Shostakovich. When the volume is turned up, dynamics are poor and the system starts to sound compressed. I suspect that the 50W Cary's simply does not have enough guts to drive the ProAc's, so I am considering replacing them with a more efficient speaker. Since most SET afficionadoes love horns, this led me to look into Avantgarde and Acapella.

I live in Melbourne, Australia. Avantgarde is available through a dealer here, but he does not have any in stock. The Acapella dealer is in Sydney (a plane flight away). I am looking to spend A$30,000 - which will buy a nice Avantgarde Duo, or a secondhand Acapella High Violon.

I have read plenty about the dynamics of the Avantgardes, but my concern is if they have horn coloration. Also, how do they image? Are they sensitive to room placement?

Would the Acapella High Violon's be a better buy, considering the pair I can potentially get my hands on have been heavily discounted? I have read that Acapella's suffer from disjointed sound because of the three different driver technologies (plasma tweeter, horn mids, conventional woofer). How much is this a problem? And are there any room placement issues? Given that the Acapella's have lower sensitivity (91 dB/W/m) would I be achieving a real upgrade by moving from the ProAc's?