Of course the Porter Cable type saw with the blade on the right and the Skilsaw worm drive type saw with the blade on the left are both circular saws. They can both be of high quality...especially the ones named. I have used both types...and others...in a career that stretches over 45 years. Both have their uses. The Porter Cable type is usually lighter and more maneuverable. I prefered it for small, quick cuts over many angles...such as cutting rafters, birdmouths, etc.. I have no trouble at all in seeing and following lines of cut. The worm drive saw does seem to develop more useable tourque, possible because of the slower blade speed, and is by far the best all around framing saw. While one can make straight cuts with either type of saw the worm drive saw is the easiest to make long straight cuts with. If I had to choose only one saw then I would choose the 6 1/2" Skilsaw worm drive saw. It is light, handy, and will get the job done. Fortunately I have both types. I disagree with those who say to clamp the saw and make straight cuts like that. Sure...you can do it. But that, and the small slip in guides, are for temporary, occaisional, or emergency use. One should get a table saw for more useable straight cuts. You can use a bandsaw for straight cuts...but again...that is not what a bandsaw is designed for. Tools are just like kayaks...designed for relatively narrow and specific tasks. Try to get the best you can for the tasks needed. I understand we all make compromises. My compromise right now is a garage FULL of tools while I fiddle around building a shop.