My Alpine (9807) puts out 23w RMS and easily drives the stock speakers to their Xmax (limit of movement for the speaker). You will hear the speakers distort when this happens. With the Alpine driving the stock speakers, you don't really have to turn the volume up that much for it to be LOUD.
Oh yea, I was debating between Alpine and Clarion when I bought my Alpine... Let's just say i'm very happy with my decision
I never did get a chance to listen to a Clarion head unit in person though, they may be just as good. I really don't know which would be better.
