Alright, a final review. Final when it comes to the test, anyway.
I'm sitting here, eGo-less, and miss it badly. (Have a bit of a problem getting a replacement.) But what shall I say that has not been said countless times before already?
It vapes great, the taste is even slightly better on an eGo than on a 510 – or an eGo without a cover. I get 6-8 hours of vaping from one battery. And no sticky fingers anymore during at least those 6-8 hours. And I was out and about with it a lot, during very cold weather. I stopped carrying other flavour/backup 510s after two days because when I took those out, they were not sticky, they were downright wet.
But instead of repeating what others already said, let me say something about carrying an eGo. With ordinary 510s, I'd usually carry the one I was vaping in a lanyard, two or three more with different flavours in a cell phone bag in my pocket, and a PCC and bottles in a camera bag in my backpack for anything that would last more than an hour or two. Let's just say I am a person who likes to make sure they don't run out of anything, so that was barely more bulk than I had with cigarettes.
With my eGo, obviously, the logistics would have to change. After a few days of trying, I was down to the eGo I was vaping in a lanyard (or, on more formal occasions, an eGo with a pen clip), and the spare battery with an atty with a different flavour screwed onto it and two bottles of liquid in a small knife pouch. Now that was considerably less bulk to carry, and I had enough stuff to vape for 12-16 hours. (Given that a lot of people vape less than I do, this should last some people two or three days. Remember how many analogs that were? Plus lighter, plus pocket ashtray…)
I've uploaded a few pics for you to see. One of the lanyards is DIY, a rubber band, basically, sewn together. The other one is a promotional gift from a pencil factory; and while the zipper thing is neat, what counts is the silicone holder for a pen – or an eGo. It fits actually both an ordinary 510 and an eGo, although I most certainly want a spare cover, so I don't have to remove it when I am home. Because once the silicone is around the cover, it stays there. (Actually, that lanyard would be neat with an eGo-logo on it, too, and maybe in a different colour. Just mentioning it, Mik.)
Another thing with the eGo is that I was surprised that people would not consider it "strange" or "bulky". I managed to recruit three new vapers down there, and each and every one said that the eGo was "cute" and that they had no problem imagining being seen with one. Given the usual preference of newbies for analog-like looking PVs, that was definitely a pleasant surprise. Especially since obviously, they would get a considerably better experience with an eGo than with a super-mini.
Also, the looks you get were different. Usually, when people watch you vape a 510, you can see that their first reaction is "That person is smoking!" followed immediately by "Uh, that's a mighty odd cigarette!" and then by an "Well, whatever are they doing?!?". The eGo does not, or only very rarely, trigger that "smoking" association. Which might make for more peaceful vaping.
So, to sum up: It's as great as others already said. It neatly circumvents a big problem for me, leaking. It is certainly very nice not to worry about battery life so much (although I never complained about that much, annoying, but manageable). That makes it a very convenient PV. It tastes even slightly better than an ordinary 510 into the bargain. And it looks good, and it feels good in my hands.
I've changed my recommendation to newbies from 510 to eGo. And somehow, I think those 510 batteries I have will last me for a very long time now.
It feels great in my hand, gives big, tasty, beautiful, billowing vapor, and has been going strong since I first charged it! I have not even swapped batteries yet, which is one of the main reasons I wanted this one, and the smaller size is great too! Great product you guys!!! If you are just starting out, or on the fence about getting one, this would be a really good one to get. 
