It will definitely perform better after a cycle or two... Li-Po batteries don't have memory and don't need any sort of breaking in, but the way the phone measures battery level is not an exact measurement by any stretch... That measurement or scale is what changes after a few cycles and becomes more accurate (on rooted phones you can even reset this, which can be convenient for a number of reasons). People don't seem to understand that and that's why you see so many pointless arguments over battery technology, etc. It's not about the battery, it's about the battery (voltage) readings the phone takes, duh.
Based on what you said, there's a couple very basic things you can do to improve your battery life tho (and signal). If you have broadband and a wifi router at home, use wifi instead of the 3G connection. Wifi is a direct point A to point B connection, a 3G radio is always scanning for a better signal or a less saturated tower, etc.; thus Wifi actually eats up less battery. There's a reason Android comes configured by default now to NOT turn off Wifi when the screen is off.
If you need a reminder to turn it off when you leave the house (so it doesn't waste power scanning while disconnected) then get Wifi Status on the Market (by Andrew Schwimmer). All it does is place an alert on the notification bar when Wifi is on but not connected (bonus: pressing it works as a shortcut to turn it off).
Finally, if reception at your home is bad enough (as it was in mine), you might still see a high battery drain when leaving the phone in areas with a single signal bar, even with Wifi on (which turns 3G off but still leaves that old
phone part of your smartphone scanning for towers and a better signal). Supposedly the EVO 3D is better about this and doesn't scan as aggressively in those situations (the 4G would kill itself scanning), but why not just get an Airave?
The Airave is a femtocell, a device that plugs into your router and creates a mini cell tower within your household... Basically it routes calls (and even 3G with the newest model) over your home broadband. Calls consume very little bandwith, and the thing is a snap to install. Typically Sprint gives it away and charges $5/month for it's use ($10 for unlimited calling minutes thru it), but the retentions department I mentioned in my previous post is giving them away like candy to anyone who computations about bad service.
I called the normal CS department months ago and they said $5, but retentions (877-775-4886) gave it away with no monthly charge when I called asking about my ETF because I was "evaluating my options" (didn't even really threaten to cancel like many have); they also gave me back my 12 month upgrade.
I really wasn't about to leave, despite the crappy signal at home Sprint is still the best deal, but they hooked me up so that isn't even an issue now! I'm very impressed with their CS after just one year, blows AT&T away by a mile. I had better coverage overall with AT&T in a few places, but that's about all I had (very glad Sprint is resisting the trend of data caps!).