Just for reference, I believe that the designation of the e2 is either the e2 executive or the e2e executive elite. Just to avoid confusion.
I looked around for a while before getting an e2e. The primary reason I got the elite was because of the lock-out tail cap (LOTC), not because of the pyrex lens. Through various sources, I came to the conclusion that the pyrex is more resistant to heat, and slightly more resistant to scratches. However, I couldn't find any report of problems with the lexan lens regarding heat, and I have read that there are NO plans to release a high output lamp assembly (HOLA) for the E2. There is a low output lamp assembly (LOLA) due to be released very soon, however. Like within a few weeks, last I heard. Also, while more scratch resistant, the pyrex will still scratch, and also I've read that the scratches really have little to no effect on the light output, visibly.
My understanding is the LOTC increases the water resistance of the e2 (somewhere I read making it waterproof, although only to a minimal depth; it is definitely not a diving light!). Additionally, it is easier to index the LOTC to the momentary-only position due to the notch in the body and the dimple in the tail cap. Good for covert operation (like I'll ever need that; but at least it is there).
The biggest things to consider for me were the differences in the bezels and the clips between the e2 and e2e. I have heard several people say the "anti-roll bezel" of the e2e is redundant at best, and obtrusive (?) at worst. The standard bezel set-up of the e2 prevents it from rolling, due to the clip. My e2e is actually sort-of a hybrid, with the new clip set-up, yet the old, non-anti-roll (howya like that string of hyphens?) bezel. It does not roll, however.

There are rumors, I believe, of a click-cap assembly coming out for the e2, similar to the one that is now available for all the standard diameter lights (6P, 9P, D2, D3, and such). Just for information. You might want to peruse
www.candlepowerforums.com and
www.186thousand.com for more information. Hope this helps. I'm very much a newbie, so consider that regarding the information above.