The Dolmar 7900 is by far the best saw out there is this size class of saws. Get them while you can. Thanks to the EPA regulations. Dolmar dealers are pretty rare in my neck of the woodsI stated this before on a chainsaw site and about got hung. lol. But the 066/660 is the most disappointing stock saw I've ever ran. It's also the most impressive modded saw I've ever ran.
When my 066's were stock they could bare out run my mildly modded Dolmar 7900.
(93cc's vs 79cc's) But in the 660's defence, the 7900 is a monster modded.
The 660 is a great saw though and really deserves it's huge cult following although not this fastest/powerful in it's class.