Love! Love! Love! I actually prefer it to my Ks, Bs, Cs for day-in/day-out wear. My 2 DC Elans are my only two bags in Epsom (pretty good for the weather where I'm located), they hold the daily necessities plus a bit (I do carry a cardholder & not a wallet, though a small wallet would fit). I don't buy bags for resale value but to use them, to have them fit my needs. And the DC Elan does that beautifully while definitely remaining under the rader (big plus for me).
I really appreciate the pocket on the back, where I can put public transport cards/parking garage cards, etc. for immediate access. Even a slim phone would work (popsocket or thick case may make it stretch out too much). The adjustable strap is great, because it goes crossbody for casual/daywear looks and can be adjusted to various lengths up to a high shoulder bag for the evening. I will be honest in saying that some colors of the Elan are better than others for evening looks. Clearly, when I say evening it's for a dinner/dinner party/etc. not a gala or somewhere very formal. But it really is a great allrounder. I've received a lot of compliments, I was rather surprised. So if you love the look and want a good allrounder, my vote is yes (if you couldn't tell that already).
Only 2 things would make the Elan even better (1) inside pocket somewhat deeper, as it is rather shallow but suffices and (2) if the strap was removable in some way, which would also make it a great evening clutch. But you can carry it with the strap off your shoulder. And, no, it really doesn't look like a derriere...
As for resale value, way back when I bought several Picotins. Not great resale value on those, at least then. They lingered for a while in my closet when I realised they were no longer my style. And I ended up selling them, about 10 or so years later, and didn't lose any money on them as they were well kept (I actually turned a small profit). They seem to be all the rage lately. Although DC Elans may not generate the resale hype that B/K/Cs do, you may very well get nearly or all your money back. And you never know how they're going to be perceived years on.