an album isn't really car audio material since records don't rare well in a car
computer test tones I can accept. CDs I cannot, since again, they are filtered below 20Hz, and most subwoofer amplifiers that are worth anything use a subsonic filter anyway.
eD is an ok company, but not my personal pick, as their representatives are completely clueless. For the money, some of their products are a good value. I do however dispute their claims to beat JL's W7 line, just as I dispute the misleading similar claims of MTX and their 9500 line of drivers.
Regarding Xmax, that's important to any design, as the excursion combined with the cone surface area determine how much air the sub is going to move.
Power handling determines very little to be honest. Power handling is merely a measure of the driver voice coils' ability to dissipate heat. The more power you put to a sub, the more heat the coil(s) will need to handle without melting. More power doesn't always mean a louder speaker.