I make the burn in with playing music of different types at low volume. I have read that white noise etc are to be avoided. I have used the method of just playing different tracks many times for burn in without any problems. Approx 50 hours of low volume playing settles everything down pretty much so more critical listening can be done.
I audited both the GS1000i and the PS1000. The GS1000i eliminated themselves relatively quickly. The treble was simply too hot in many cases and the overall presentation was bright. The exception was classical music - it sounded good in general. But the obvious difference I noticed is the "all round capability" with the PS1000. It doesn't matter what I tested them with - they sounds refined and balanced with a high detail level. No sibilance or anything like that. Before I made this decision I tried the GS1000i straight out of my Thunderbolt with PowerAMP and they sounded more balanced in that environment but was obviously underpowered. So my expectations on the GS1000i was higher - I didn't expect that the PS1000 was going to win so completely.
But the audition made it very clear: if my musical preference had been just the classical, the GS1000i could have been a good choice (they sounded very good in general in that genre). But the PS1000 simply sounds more balanced and refined - everything simply is in place with them. The treble of the GS1000i was simply too much for my liking, some female voices was really "ssssssssSSSSSSSSSSSsssssssss" - even if they become a little bit better after some break in (made by me during the audition).
I began the audition with my RS-2 to have the basic reference set, from there I went to the GS1000i and finally for the PS1000. I like the RS-2 very much because they have the optimum combination of a warm sound but clear and forward on the same time. The RS-1i is a little bit too bright for my liking. The GS1000i to my ears is more in the line of the RS-1i rather than the RS-2 with flats. The PS1000 is in comparison going in the same direction as the RS-2 but adds details and soundstage etc to the mix. But my impression is that they basical balance is similar - i.e a step forward in all aspects without any negative effects. The GS1000i is a step forward in some areas and a step backward in others - I can understand why Grado developed the PS1000.
What I will do later today is to connect the system properly, I am now powering the PS1000 straight out of the MacBook Pro for the low level break in.