Well, now that the rough boys have weighed in, a little opposition is in order.
I have had a Milwaukee worm drive for over 20 years. It weighs north of 16 lbs. When I encounter need for it, its use is apparent--- and rare.
It's kind of difficult to mention "circular saw" and "accurate" in the same sentence. With a really good one, you'll get great, accurate cuts. But, never rely on a circ saw's tool markings for accuracy.
Use it correctly: proper blade depth, use a rip guide, stand where you should, don't over-reach, have the work properly supported, etc. and you'll be fine. Spend way less, too.
I've had several, but I'll go for my Porter Cable 7.25" anytime. It's the only one available for lefties. I'm R-handed, but I prefer the L-hand model (as do some friends), because I can keep sight of the cutline more readily. It also has one of the biggest base plates around.
