Proac 2.5's-something not quite right- ideas?

Ok Audiogoners I've just recently required a pair of Proac Response 2.5's.
My system is Ayre CX-7,Ayre AX-7-using custom made balanced interconnect (tried Cardas Golden Ref.happy with this)and Vantage Marina Speaker cable(bi-wire)-my old speakers were Proac Studio 150's.
My sound before was excellent-worked with my wide musical tastes,subtle and detailed when required and enough oomph when playing Rock or Electronica.
Typically I though my speakers were the weak link and have always wanted to hear/own 2.5's.

What I am hearing with the 2.5's is a jump in scale of presentation and more air/detail around instruments,on certain recordings it sounds really great on others something is missing,the smoothness and clarity I associate with the Proac sound.
The second problem is the scale of the bass,it may just take adjusting to and whilst it doesn't sound overpowering in terms of the overall recording (vocals/details etc. are still there)it really does seem too much for home listening-more like a gig or club experience.
If I put the 150's back in,the bottom line is they sound more musical overall.

I don't believe it's my room which is large-18 feet wide by some 30 plus feet long-I have 3m high ceiling -whilst speaker placement makes a slight difference (I've been messing about with that)it is not a major influence on the general effects.
I've also tried ceramic tiles on my carpet with the speakers on top-again not a major difference.
Everything in my system has been checked-the speakers are set up per instruction and the replacement effect of the 150's proves nothing is amiss imho.

I have several theories as to what might be wrong-the only previous owner only listened to Jazz and Classical and not at as loud levels as I do-the speakers have not been used in the last two years.
So if run in/break in is a factor (I've only got about 8 hours on them)can I expect the missing resolution to come into focus?
Can I expect the bass driver to change?- since perhaps it has never been fully tested with fast/deep modern bass.
Does my increased listening volume mean more break in was required anyway?

My biggest fear is the scale of the 2.5's is not to my taste and that they are so revealing that I am hearing a grain in some recordings that I didn't hear before.

I've read enough about these speakers to know some how I'm not getting what I should and I instictively know on many of the tracks and CD's I'm playing that I am not getting the enjoyment I was before despite some more space and detail.

Thoughts?