As much as I hate saying it, I have also had those white plastic Bose for about 10 years now. They do a fine job outdoors without distortion (which I've heard on many others when played above a whisper).
However, I have also heard true audiophile outdoor speakers made by Near (out of New Hampshire), if you want to spend the bucks and can find them. They are truly awesome, and they have several models. Good enough to bring indoors to the main rig, if you want to.
Here's a link that you may want to check out:
http://www.audioreview.com/cat/speakers/outdoor-speakers/PLS_2745crx.aspx
Enjoy,
Bob