When I got my extended battery the guy at the Verizon store also told me that these batteries did not develop a memory at all. All I can say is... old habits die hard!
I still took it home, depleted it all the way (it came with about a 60% charge on it) and then left it on the charger the entire night. Then I took it from full to shut down three full times before ever plugging it in prior to the phone shutting down on its own. My philosophy is this, "it can't hurt it any" if I do this. If they are right about them, then so be it, I still haven't hurt the battery by running it through 3 full power cycles right off the get go. But if they develop even the slightest amount of memory, then I have the peace of mind in knowing I did everything I could do to help extend the battery as much as I possibly could.
When I got my DX I found the stock battery to be absolutely horrid. I was getting the, "please plug into charger" 15% alert within 4 hours of unplugging. Mind you I was really playing around with it a lot, but even once I started leaving it alone more, I still was not happy with the stock batteries performance in the least. So it got me to wondering if perhaps my phone had been 'played with' before being shipped off to me, and the battery suffered from not starting it's life out the right way.
What I mean by 'being played with' is, when the DX was first released and was on back order everywhere I would go down to my local Verizon store from time to time just to 'play with' what ever DX they had in the store at that time. What would happen is they would get a few phones in, and while they were waiting on whomever they had called on the list to come pick their phone up, they would let the customers demo one of them to try to 'hook' them into getting one. That's actually how they hooked me. I had gone in to purchase an original Droid (during the buy one, get one free promo), and they had a DX on the counter so I started playing around with it. Played one game of NFS Shift and couldn't believe how awesome the graphics were for a damn cell phone. They had me hook, line and sinker after that.
But at any rate, I remember thinking, "boy I wonder if they're charging these things correctly before they let customers just play around on them? If not, I'd hate to get one of these devices and have a sucky ass battery because they didn't break it in right". And even though I didn't get my phone from them (ordered mine directly from Verizon's website), I wondered if perhaps before they even packaged it if maybe the employee's did anything similar, just playing around with them before they packed them up and sent them off. You just never know what exactly your phone has actually been through before it reached your finger tips. I'm sure most of the people picking up their DX's from the waiting list had no idea that customers had been playing with their phone all day.
And what really got me thinking something like that could have happened with my phone was because after getting the extended battery for my DX and doing the same 'break-in' on it that I did with my stock battery, it immediately started lasting at least twice as long as it had on the stock battery... dispite only having roughly 20% more capacity?
The numbers just didn't add up to me?