Quote Originally Posted by binka_nugget
I don't have much experience with Collies but I thought I'd add in my personal experiences with Shelties. I've found that Shelties are generally high strung and would love nothing more than to run and bark all day. Of course, there are exceptions as with any breed.. my boys are laid back most of the time. They get their occasional "bark, chase, bark, ball, bark, bark, bark" moments.

They're known for being barkers (yeah, I know.. it can be "trained" out of them.. but it still comes VERY naturally to Shelties) as well as being "reserved" with strangers. Both my boys hold conversations (LOL) and are reserved with strangers as well.
Yeah, my shetland sheepdog never stops barking.