i figured i'd post this for potential se215, (but want bluetooth capabilities too)
just got my hands on these
Mine can be driven from HTC M8 no problem. It also works well with portable amps/DACs. My Fiio Q1 for example. Because of its high sensitivity, I find that the SE215 needs very low volume to be set at the source for it to give acceptable sound levels, perhaps more than any other IEM I own. So I have to make sure I turn the volume way down before inserting the SE215.
The SE215 sounds good, but they're also not the best, particularly when it comes to soundstage & clarity. For bass the SE215 is ok, there's enough of it although to my ears they sound rather slow and bloomy.
In MY limited experience, the MeeAudio M6 Pro gives better clarity but soundstage is so so. The MeeAudio Pinnacle P1 does everything better, including soundstage.
If you're not adverse to chinese made products, then try the Xiaomi/1More Piston 2.1 or the Venture Electronic Monk Plus earbud, they do really well in the soundstage department. Clarity maybe not so much.
1) No issues direct out of a phone, these work very well. Most dynamic driver IEMs don't require much in terms of fancy equipment to drive, so you shouldn't have issues unless your phone's built-in sound is really really crap.
2) I perhaps have really high expectations for what I deem as "wide" sound stage, but I always peg "wide" as perceptually sounding like the music is extending beyond the cups/earpieces. This is why I didn't feel the HD598 sounded like it had wide sound stage when most people seem to think so, because I didn't find the sound really extend very far left and right. On my pair, it just sounded like it was still contained in a space within the distance of the cups.
Explanation aside, this is my humble personal opinion - pretty much no IEM, imo, has "wide" sound stage. The widest I've heard are the Sony XBA-A3, XBA-Z5, and XBA-H3, but even then I'd say the sound stage on those earphones just about matches a closed headphone like an M50x.
Note though, that I've never heard the EX1000 or the MDR-7550 so maybe those might be comparable, or even better than the XBA hybrid series in the sound stage department.
Feel free to ask more questions, hope I've helped!