I'm just a newbie, and I've been getting bogged down in researching a replacement for my dearly departed Nuforce NE-700x's, and some advice would be very much appreciated.
First, background. My first step away from randomly selected $10-20 walmart buds were the ~$30 Soundmagic pl30's, but they didn't sound much better to me and left me utterly unimpressed. When they died, I bought the NE-700x's for $65, and I was completely blown away by the sound quality. I heard details I'd never heard before, the fullness and texture of instruments and voices, the deep bass that I hadn't known existed. I love being able to hear the vocalist's breathing, the squeaking of guitars, quiet background instruments, etc. And the separation between instruments was awesome. I also love it when, very occasionally, something will sound so realistic that I have trouble telling if it's in the music or from my actual surroundings. That said, I think they could have done with a bit more isolation, and I had trouble keeping them in my ears when walking or exercising (despite trying lots of different tips).
I listen to wide variety of genres, including folk, classical, metal (death, power, avant-garde), rock (prog, post, pop, classic), post-hardcore, electronic, drum and bass, rap, etc, so I need something versatile. Vocals are especially important to me, so I think it's important that mids be full and not recessed (although I saw of a review of the NE-700x's that said its mids were a bit recessed, and I never noticed, so maybe not?) I'm also partial to strings.
I definitely want something that matches or exceeds the bass of the NE-700s, but since I also care about detail I'm worried about bass that bleeds into the mids and treble and muddies everything up.
Accuracy rather than fun or artificially colored music sounds good in theory, but it looks like that's more a trade-off of bass for highs rather than an actual true-to-life sound? Or might land me with something that sounds flat or thin? The pl30's were apparently reviewed as neutral, and I didn't like them at all, although may just be because they were only $30.
I'm also curious about trying something with a better soundstage.
Sound leakage when they're in would be a major minus for me; I like my music private.
Finally, spending this much money on IEMs is an extravagance for me, and I like to listen while exercising, so I need something durable and well-warrantied.
Anyhow, I've been digging through reviews looking for options, and so far the RHA MA750, or the RHA MA600 if I'm cheap, are the most tempting. A lot of reviews say the MA750's have great bass but are balanced overall, and they come with apparently great build quality and a 3 year (!) warranty. But a couple reviews report the bass occasionally (but apparently not usually) bleeding slightly into the lower mids, and a couple claim that the mids are recessed (contradicting other reviews that say they're perfect). Some reviews seem to take issue with the treble and dark (a term I'm having trouble not associating with muddy) sound, while others say the treble's great.
I also found a review for the JVC HA-FXT90's that looked promising, but apparently they've been discontinued. And I looked at the Shure SE215's and the Brainwavz M2/3/4/5, but I think the MA750's look far preferable.
But am I overthinking this? Will upgrading from a $65 IEM to a $90-120 IEM be such an all-around improvement that I won't notice subtleties that the reviewers pick at? Will the difference be comparable to that between cheap earbuds and the NE-700s? I have trouble imagining that it would be, but when I was using $10 earbuds I couldn't imagine what I was missing out on either.
Thank you to anyone who made it through that the wall of text, whether you have advice for me or not. :P