srobak:Although I have a set of about 5 songs I can run just about any speaker, amp, or headphone through and know if it is worth the money or not. :)
Sound quality is one thing, but just about equally important with in-ear headphones is comfort and seal. You'll want to make sure you take the time to get the proper fit before making a judgement call, which can take more than a few attempts to achieve (esp with the Custom models).
Something to think about!