First, I want to mention that there's already a thread with this exact same title. You might want to go read that thread instead of posting a new one. The search box is your friend.
That said, I really enjoy my X10's. They are VERY variable based on the eartips you use. I've tried the stock gels, Complys foams, and am now using custom tips. With the stock gels they are pretty bassy. With Complys I got a good balance. The Complys are generally considered bassy, but I think since I was inserting the phones deeper in my ear it was bringing out the treble. With custom tips, they are pretty balanced and a little toward the treble side. Definitely not a basshead phone with custom tips. The bass is there, and I'm definitely getting a seal because if I EQ some bass up it's solid, but the treble really gets more dominant with custom tips.
The short version is, I think the X10 is a great set of earphones, and if you experiment with tips you should be able to get the sound you want. That may require buying something other than the stock gels though. The gels are very comfortable, but not my favorite for sound signature.
I haven't had any big issues with microphonics. I do have a problem if I let the cord get twisted, but if I keep the cord straight I don't have a problem. The gels are worse than the complys or custom tips for microphonics too. And I mostly use them at a desk or in bed. X10's are definitely not headphones for working out with, especially with the gels.
Anyhow, that's my two cents on the X10's. I'm very happy with mine, but I invested another $100 in custom earmolds.