I think I will probably not get the E2's. My sense is, as lindrone implies, that it won't be enough of an improvement over the PortaPro to make it worth it. Plus, and I know this won't win any respect on this forum, but I think the E2's are kind of ugly, to the extent that they can be seen. If I'm going to spend a lot on earphones, I want to use them a lot, and for me that means I want them to look nice and to look unobtrusive. The e2's to me look unusual, which means they look expensive; the e3's look more "normal" which means they don't look so expensive. I don't mind spending a lot on something like this, but I don't want it to be obvious that I have done so. Also, I think the e3's look a lot more rugged than the e2's--and I'll want to be able to shove whatever I get in my pocket, and not have to worry too much about it.
I've definitely been convinced that I won't be happy with the EX71's. Now I am down to a choice between the e3's and just sticking with the PortaPro and saving my money. Wildone asks what do I have to lose with the money back guarantee? I have about $170 to lose, since if I buy them and really like them, I'm out $170.
And then maybe more--who knows where this could lead? But my intention is to find one pair of earphones that I like, and stop. That is one of the reasons that I am willing to spend a lot once. I did that once before--I didn't mention this previously, but I've had my PortaPros for about 15 years. Not this pair, actually--they broke a few years ago, but, of course, Koss replaced them (love that lifetime warranty). So I am willing to stich with something I like for a while.
Which brings up another option: I didn't list the Etymotic earphones among those I was considering, since I don't want to pay as much as the ER-4 would cost, and I hear quite mixed reviews of the ER-6 (and they look flimsy to me). But I might be able to be convinced otherwise on either. After all, I think I've shown a williness to buy something and stick with it for a while. Which is one of the reasons the ER-6 is less appealing--it just doesn't look like it would last as long. it looks like I'd walk through a doorway, catch the cable on a doorknob, and rip out one of those skinny wires.
But otherwise, right now I'm leaning toward getting the Shure e3's "at some point." Maybe if a really good deal comes along. Or maybe tomorrow.