Heartsmart - I've had similar questions to you before recently ordering my ce6b.
I found the review against 1964 ears at:
http://www.headfonia.com/6-driver-shootout-cosmic-ears-vs-1964ears/
useful.
Can't really help with your questions, other than the conversations I've had with cosmic ears on the differences between the p and b, as well as the bass response of the b. CE were pretty quick to confirm that the bass isn't bloated and doesn't bleed on the b, but it is enhanced. Given i'm the sort of fellow that will rely on a portable amp or alternatively eq, the b is going to be the right answer to substitute for doing both and get an enhanced bass response.
There's another article, which compares CE before they moved to the "b/e" versions to other ciems, with a recommendation to CE to change two of the dampers to be more bass geared.:
[COLOR=333333]"Phil Gartell, owner of Cosmic Ears, tells me he tuned this model based on feedback from various local performers who he works with. Apparently he had a choice of two dampers for the sound tube handling low frequencies. Based on artist feedback he chose the damper resulting in lighter bass. I advised him the other option may have been better, and he seemed to agree. So moving forward these might be ever so slightly more appropriate for regular listening as opposed to their current ruthless nature"[/COLOR]
http://www.innerfidelity.com/content/totl-madness-24-top-line-custom-ear-monitors-reviewed-companies-john-grandberg
This might be the reason that CE started developing the B/E lines.
In any case, based on everything I've read, including the previous comments in this thread, the B is the right answer for me. Depending on what you prefer, might not be for you.