Not sure by your post, but Im hoping you didnt see an 8000 at a box store. That saw is shipped PHO to dealers only, the carb is not tuned out of the box either.
A dealer orders the BAR for it, it comes with a sprocket guard, some put them on, some dont, it's only 1 little bolt..
The dealer preps the saw, puts a tach on it, and sets the MAX no load engine speed.
Same with the CS-670.
Bottom line is it's a real hoss of a saw, still starts easily and runs like a top, lots of grunt. For the money, I dont see anyone being diappointed. NO it isnt a screamer, no it wont pull a 48" bar of full comp in 60" of Hardwood...but it can hold its own.