Battery vs. AC. What's better?

[eoniverse]

Does anyone think it damages the Archos port to leave the Archos hooked up all day while viewing movies and listening to music while using the Archos AC Power Dock (vs. the battery)?

This thought is coming from using Gomadic adapters in the past. I had used adapters to power a newly purchased Creative Zen M and an Archos 504. The Creative data port fried (rest of it worked). The Archos locked up and would not unlock (tried everything on both. multiple reset's , reformat, etc....). Creative did this after 5 days using the Gomadic. Archos after 3 days using the same Gomadic with a different tip. Both returned as defective and money refunded (different stores).

But it makes me wonder (if the after market stuff should be avoided and...) if a particular viewing method would make the device less susceptible to power issues