I think the EX1000 form factor for me is very comfortable, fit very snuggly (better than Z5). I remember headfonics also claimed that the EX1000 has the best form factor for an in ear.
For the EQability, this is the first time for me to hear it about the EX1000. Could you give me some EQ(or links to and thread) so that I can find out more about it. Thanks!
Unfortunately last time I didn't save my EQ, but it's a pretty simple low-shelf with somewhat of a small Q factor on the subbass region at around 100Hz. I remembered adding a 10dB boost on one time and I immediately noticed that it gives me that tight, but really hefty punch. Other IEMs like my 18+ or the HS1551 basically turned to mush or just gives a really unnatural and boomy presentation when given the same treatment. This one just eats it like a champ. Barely distorting at all, if any. I haven't really experimented with tuning it to a specific target curve though because frankly I'm really happy with the stock sound without the foam dampers. And tuning it to a specific frequency will need me to get a better gear than just a $16 mic
Comparing it with the iSine 10 last time the EX1000 can deliver significantly better punch quality and sounds much more natural. Also it really doesn't have to rely too much on EQ like the iSInes do.
I've trawled a bit for threads talking about EQing EX1000 but unfortunately it's always mentioned in passing on the EX1000 official thread. Can't really help you on that I'm sorry