I was listening to some Jazz last night with my HD580's and brought over my 225i just for a quick listen, and the treble gave me a headache in about 5 mins. I was using them on my Headroom amp, which is a warmish sounding amp but still, Grado's just don't tolerate certain amps and music very well at all. I think the treble on the 225 bother me more than on my 325, probably because the extra bass on the 325 evens everything up. Going to be selling the 225i for sure and maybe both. I really don't need 5 sets of headphones.
Yeah I think going straight from the HD580 to a 225 would take quite a bit of adjustment time as they are very contrasting. I love Jazz with Grado's, they put you in the middle of the band and the feel/impact of the instruments is ideal. But certain aspects of the freqs can get annoying. Especially with older harder recordings (classics). I'm finding my Foobar EQ (latest version with 31 bars) is becoming my best friend! As little as 2db down at the treble peaks can make them much more tolerable for Miles and Coltrane :)
The 225i are such a great Grado, maybe you should just try a little EQ to suit your personal tastes. It works for me!