I'm what you call a skeptic. I would suggest that unless you've listened to a wide range of speakers and associated equipment, and have a pretty well educated ear for what people mean when they come here to wax poetic about how the artists seems like they're almost in the room...... You probably won't notice anything at all. Your big initial differences moving from mediocre to better equipment, especially speakers IMHO, will far outweigh any perceived difference from 'break-in'. There's just too much associated with just simply getting used to the sound over a given amount of time.
I've been a part of this hobby for long enough, in a serious enough manner, that I have 4 different amps (Including a decent tube amp and a modded Virtue M-901), several sources including a dedicated music server with a pretty darn good DAC, a SACD player, and a turntable, and two rather good sets of speakers in my listening room (including GR Super-Vs) - along with a mess of upgraded wires and battery power supplies - and I can truthfully say that not once have I suddenly realized that after such and such many hours on any given piece of equipment or ancillary device, have I thought it sounded any better than when I first got it. Except maybe the tube amp. As it is I have to turn that thing on and leave it warm up for a good half hour before I like to listen to it anyways, because I want to hear the music and not the equipment.
Of course, as with all subjective subjects, YMMV!
Regards
Dave
