I have some 2006 Grado Sr225s with quarter-modded yellow 414 pads that have become my favorite headphone (formally DT880 250 ohm was my fave). I've seen an old thread here where someone said they preferred (I assume stock) SR225 to RS1. Anyone else here have the SR225 with the simple 414 quarter mod that prefers it to Grados higher in the line such as RS1 or PS500? I'm feeling upgradeitis and was wondering how different those two models might be. Thanks!