I have not heard the it01. I was not personally a fan of the SE215, overall I just didn't like the build or fit of them. Gr07 was my gateway drug into this hobby. After not finding what I was looking for I took to the internet and upon giving my information I was immediately told to grab the GR07, and I couldn't have been happier that it was my first real dive into IEM's. I've since upgraded pretty significantly, but they felt great to wear, they sounded ideal for me. There is some concerns about them being sibilant, and it wasn't until I tried a great many other things that I realized what it truly meant, and I definitely see what people mean.