Rega Brio-R Break-in time.

I just bought the new Rega Brio-R integrated amp. This is the third day I am using it now. I have been trying to burn it in but only have about 20 hours on it so far. I have mixed feelings with it so far. Everything sounds great except for one part. The upper midrange and lower treble sounds shrill, bright, and thin. It is unnatural. I wince when the T's and S's come on with singers. And with any instrument in that range it also sounds unnaturally bright. I'll give it another 100 hours or so. I really hope it changes with break in because the amp does so many other things right. My fingers are crossed.
Anyone else have any experience with Rega gear during break in?