Altho' I'm not an Europa owner, I'm a GMA owner. From what I can tell from my own experience is that the most significant improvement will occur until the 100 hrs mark. From the 100 to 300 hrs mark the improvement will be less dramatic i.e. you'll the speaker get more refined. How well you can perceive this will depend on your hearing abilities & your system's abilities to "show" you this. BTW, I'm in that 100-300 hrs period myself.
Atleast in my speaker there is internal cabling from both Audio Magic & Jena Labs. The Audio Magic wire needs 1000 hrs to break-in! *If* memory serves me correctly, Roy told me over the phone that the latest production runs of speakers are now using only Jena Labs as this cable is just as good but needs much less time to break-in.
My user manual informs me that I should exercise the speakers with both soft & loud passages of music to free up the woofer rubber surround. This will help tremendously in the speaker's ability to reproduce music at lower volumes - 65-75 dB SPL at 9 ft (for my situation with these 3-way floor standers). I can personally tell you that playing Bob Marley tracks & other Blues tracks at high volume has indeed helped me enjoy this speaker system at the above mentioned volume levels - I can hear all the details of the music at low volumes. This sort of trait is very typical of electrostatics & ribbon tweeter based systems but I'm thrilled to have it in my dynamic/cone-driver speaker!
FWIW. IMHO. YMMV.
