I've been doing some research as to how I'd like to progress through Grado's lineup. I've been using the SR60i for a few years, and while I'm happy with it I can't help but wonder how I could upgrade in the future. Ideally I'd like to have headphones that are forgiving of poor recordings and don't cause any fatigue after long hours of use. I currently have no problems with my SR60i in either of these areas.
Googling has led me to believe that the SR225 would be a proper upgrade choice. I've read that while it is only the second highest in the prestige series, it is much more forgiving than the series' flagship SR325 and is an all around more "fun" pair of headphones. Looking at the flagship headphones in the reference and professional series it is apparent that the RS1 isn't what I'm looking for at all. I've read a little about the PS500, but the only reference to forgiveness I've seen is only saying that it is more forgiving than the RS1, which doesn't necessarily mean it's forgiving on its own. What little I've read about the RS2 alludes that it may be more up my alley than its big brother the RS1.
What I'm asking is how does the SR225, RS2, and PS500 fair when it comes to forgiveness and fatigue? Any first hand experiences? I want to know if I can listen to my music for 5 hours at a time without getting fatigued like I can now and know that my low-fi recordings aren't going to become unlistenable. Based on what I've read the SR225 should provide me with what I'm asking, but if the others do too I don't see why I wouldn't choose them instead. The lightweight of the wooden housing and leather headband are very appealing features I'd like to have if it I'm not sacrificing anything for them.