Do you run it balanced (DAC->amp)? Cause if not than you've only got 'half' of what you can get balanced.
I swap sometimes my Sunfire Sig600 to ST-1000 from my friend that has the same Aerial 10t as I do. In both cases I'm happy, but love my my Sig600 for larger and wormer sound. Try to use your integrated as an amp only if you still have your old preamp.
As to break-in time I doubt that after X00 hours it will show significant changes only slight ones.
I swap sometimes my Sunfire Sig600 to ST-1000 from my friend that has the same Aerial 10t as I do. In both cases I'm happy, but love my my Sig600 for larger and wormer sound. Try to use your integrated as an amp only if you still have your old preamp.
As to break-in time I doubt that after X00 hours it will show significant changes only slight ones.