Have you actually heard any of these? You're making some matter of fact statements there.
Anyway, on a personal note, can you please stop making a new thread for every question you have that is related to your original inquiry? I dont know exactly why, but it's driving me nuts. They can easily go into one thread where you can ask all the questions you have about what you're looking for in new IEM's. This is completely personal and I'm not speaking for anyone else. Pretty please. Don't take this negatively as I really do want you to find what you're looking for.
Now on a more positive note, since you're budget is already at a sizable $300, maybe save up a bit more for a few weeks and look into the JVC FX700 or maybe even the Westone 3 if you can deal with supposedly finicky insertion. The JVC FX500 is a lower priced option at about $160. Both the JVC's are supposedly pretty low on isolation.
You can look some of them up in the links in i2ehan's sig.