Hello,
In response to your post, there can be many different factors contributing to your experience with what seems like low battery. I am not sure what settings you have currently configured but perhaps you can set the following things to possibly increase battery life:
-decrease screen brightness to half of below half. (I found with my macbook pro that by doing this, gave me about an hour or two of battery life.)
-turn off bluetooth if not being used.
-check out what programs are running in the background. (if there are programs in the background constantly doing different things like checking the internet or downloading or streaming etc... this could affect battery)
-application usage: be aware that the kinds of apps you use cause the system to estimate the amount of battery you have left.
-After researching over the net and through apple, it does not seem to have any information anywhere stating that the i7 will take more battery. on apple, it simply claims that "web browsing" will give you 5 hrs of battery for 11" and 7hrs for 13".. anything else like watching movies or looking at pictures or reading or editing things etc... may again cause the system to estimate lower than 5 or 7 hrs of life.
-Finally, in the end, you may be correct, because the i7 is more powerful, may take more juice than the i5... Yet, both the i5 and i7 are low voltage.... so if 2:30 min was the max for the i7.... ... many people will be complaining in the next few days/weeks about this. We will just have to wait (that is if any of the above does not actually change your experience with the battery)
**I am currently waiting to receive the i7 13", will hopefully arrive aug 1-3...
Hope this helps,
Macboy