I currently have both Grado models - RS1i and GS1000i. My original plan is, ideally, to keep only one pair.
My source is an iMac with FLAC files and the DAC/Pre is the Meridian Explorer. It's a simple system, but seems to work well for the level of use I have.
My observation of the GS1000i is that they are astonishingly detailed and precise. The cups over the ears are nice too, rather than direct pressure on the ears like many headphones. They have a full range sound, but I do find the mids a little recessed and it's almost like the upper frequencies have been lifted a little and they are not bass heavy. However, their texture and delicacy is amazing.
The RS1i have a completely different sound to me. Does anyone else find this? They seem like a much flatter response with a fuller sound, with seemingly more groove and stand out mids. They don't have the detail retrieval of the GS1000i and are less impressive on first listen, but they do sound very nice indeed.
It's tricky to say which I prefer, as I have only owned the RS1i for a few days, but sometimes I find the GS1000i so detailed it's like having your head inside a speaker! On first listen though, the GS1000i are mightily impressive, but are more fatiguing.
Just wondering what you have experienced here through ownership or demo?