Thank you both for your thoughts. I think you've tried to help me in my quest.
@funkymartin,
I agree wholeheartedly with your comment about source. I can hear that my 225i/(e) would be something much better on a vastly better source. (That is in fact another option rather than upgrading the headphones.) I have been looking very closely at the Naim UnityQute 2. I could run S/PDIF from my Meridian Explorer (ME) straight into the Qute, for gaming and files on the PC. It has DAB, and USB pen drive for playing audio files. Desktop sorted then.
The ME is described as having a smoother sound generally, which can be better for longer listening sessions. I thought that might be a wise choice with Grado. I wasn't necessarily right though. The ME paired with already warm sounding Grado may have gone too much the other way. Having said that I still get a crystal top end and I defy anyone that criticises the 225e treble. Rock music zips along and does all kinds of amazing stuff. Therefor I am happy I made a good choice.
Maybe I should have just bought the Audioquest Dragonfly V1.2 for an even more energetic and exciting listen. (It is after all awarded best DAC up to £300.)
However equally getting a great headphone would have a similar effect. It would improve all the devices which I plug my headphones into.
I also get the impression that the 325 does everything slightly better. (I will address fjrabon's post next which questions that.) Quite a few folk have said the same as you. It seems even more poignant since you are comparing the 325i with the 225e.
@fjrabon ,
Thanks again. Weight of the SR325e I never thought would be an issue. The 225 is most definitely a light wear, but the 325 is only 40g heavier.
More sibilant is hard to understand, since the 325e is rapturously praised for its new top end. It's something I will look out for a soon as I get my hands on some 325e though. (I think that will be my choice.) The RS2e may be a better headphone, but I can't judge how much better. I am relying on pro-reviews. Since there are not any RS2e pro-reviews, I put stock in 'better the devil you know'.
I half expect the 325e to be just that bit clearer and more revealing. A touch of excitement I wish for over my current set up. It would be interesting to hear what you think if you went back and auditioned the 325e now. Since you have grown accustomed to the 225e through owning it, the 325e could be heard through fresh ears. (As mentioned above I struggled to hear difference between the better ME, and the on-board audio. Going back now is clear as daylight.)
Did you ask how much run-in the headphones were that you auditioned. I am wondering still about your experience of 325e sibilance. Just maybe they needed some more time on them. SR325e owners do sing their praises, and some even prefer the brighter more treble hot 325is.
Finally though as said, the 225 was never that hotly regarded. That was always surprising given the rest of the SR range all scoring five stars. I have the box of my SR225i with carry case bundle, and on it is Hi-Fi Choice 4/5 stars 'Recommended'. What Hi-Fi only ever gave the original SR225 4/5 stars. Only users seem to like them, but then we might be biased, haha. Personally I like the SR225i/e, but I can see where it needs upgrade. My theory is it's because the plastic cups can not handle the extra speed and clarity from the 225 upgrades. Over the 125 I mean, i.e. the grill and closer matched driver.