Ok time to explain a bit more on recent decisions - I've had time to articulate some high level thoughts. YMMV, You Can Go Your Own Way etc...
EXT - why should it leave me?
While the DD mids are without doubt fantastic, and I've had many magic moments over the last while, it lacks my sub bass needs - mid bass is however very good. In addition, while I love the EST treble, it at times isn't sufficiently coherent for me - I hear it sat slightly outside the main body of the music, too much to the front. Some genres have got a bit too spicy in the uppers too. The mid focus limits my choice of genres a bit too much, and means a week or so often passes without me thinking of them - overall, my measure has become mostly how long something sits in its case, not exciting me enough to reach for - that's too much cash tied up at this level. Important to note also, I listen to a very diverse range of genres, some of which fall victim to the above challenges, others don't - as commented only today, female vocals are some of the best presented I've heard on EXT - Agnes Obel for example sounds incredible... if money no object, or if I wasn't curious on some others, I'd hold on to EXT for the select genres and albums I've loved.
Z1R -
I've had some fit issues - at times, the right ear pops out. At best, I need to keep relatively still. But, they excite the hell out of me - and put a smile on my face when time to indulge with quite a lot of my library. The stock hybrids in the largest size work well, I'll have to seek more out or something similar - tried a few in the collection today and Azla Short Standard in large worked very well... need more time to ascertain if I'm happy with the sound but initial impressions are good. I had considered Z1R an all-rounder in the first week or so in that it works with any genre - I've found the odd crack though where treble zings a touch too much. In terms of fit, I can't classify as an all-rounder now either - even with the best fit, it requires occasional adjustment. I couldn't ever take them on a train, flight, go walking etc.That said, where it works, it works beautifully and like my NW-WM1A, a classic and a keeper.
Thunder
To date (about two weeks), this is by far the best IEM to meet all of my needs - any genre, any listening scenario, for any duration as comfort is absolutely top notch. Calling it an all-rounder feels like a bit of a disservice - in my experience, it has fantastic technicalities, wonderfully engaging and has yet to put a foot wrong - nothing has sounded offensive, not once. It has excellent sub and mid bass, superb clear mids, and just the right amount of high end frequencies... that coupled with a wide, deep stage, plus excellent layering and imaging. From ambient to techno, indie rock to jazz, they all sound bloody wonderful.
What next?
Thunder has been an incredible introduction to Aroma Audio and the path to Jewel is now commencing, hence my decision to sell EXT to start gathering the funds. The only spanner in the works could still be X as I've heard and love it - Jewel will be a blind buy but I'm pretty confident based on existing impressions here and my love for Thunder, that it'll be the right decision.
Oh and Traillii still absolutely wonderful, and sits firmly at the top of the table for now - even with Thunder getting more use.
Anyway, Sunday ramblings conclude - "a journey of a thousand miles, begins with a single step" springs to mind - it has been quite a journey for me over the last while, and learning a lot about what best suits my preferences with every step. I love the exploration, the discussion, the 'chase' and overall hobby, and great to share with like minded folks here.