Glad you liked the iGi/GR8 Don Gringo. I wish there were a local place I could try out the GR8, just for kicks. While the iGi was inexpensive enough to pull the trigger on blindly, I won't be shelling out $300 on the GR8 just to give it a try, after my experience with the iGi.
The worst thing this has done for me was make me question Grado's commitment to quality. It's left me scratching my head. While people argue that Grado's headphones are poorly made, I've always attributed that to some kind of vintage charm, since nothing ever felt particularly cheap to me (SR60+), and I've had many Grado/Alessandro 'phones. But certainly to me, the iGi is lacking in both design and SQ. To my ears they were boomy and compressed. Also, they just wouldn't stay in my ears, with any of the fit kit. Always felt like they were slipping out.
Anyhow, none of that should/will change YOUR appreciation of them, so again, glad you're enjoying them!