I've not heard them personally, but they seem to be a decent choice if you're going to upgrade without an amp (they're 2-ohm, like the factory speakers).
Amping them will blow them,
As an alternative, contact MusicarNorthwest (or check out their web site). With their amped system, it's possible to clearly hear the stereo with the roof & windows open. Definitely a huge improvement over stock in sound quality and available volume.