I have spent thirty plus years doing construction and renovations. While that time, we have used and even abused, most brands, styles and sizes of hand held circular Saws. (I personally was never complex in the abuse part). Having employees, means having abuse. It's surprising what some habitancy will do with someone else's equipment.
The first circular Saw I ever purchased was a Skill 7 1/4" Saw, with 2 1/4 H.P. I was eighteen at the time, and had just decided I was going to be a contractor, when I grew up. (if I grew up). The unit I purchased was not my first choice, as it seemed kind of costly at the time. The owner of the lumber yard I was dealing with, also happened to own a large construction company. When he Saw me carrying the saw I chose up to the counter, he inquired how long I intended on being in business.
Me being the cocky sort, said something along the lines of forever. (Failing didn't seem even remotely possible, at the time). He said if that's the case, I'd best consider my selection of saws. My selection was apparently a poor one. He steered me to the Skill saw I ended up with. Now, thirty years later, the only repairs ever needed on that saw has been two cords, and a set of brushes. The cords don't stand up well to a saw blade.
That singular saw has a set of bearings in it that will keep the blade spinning for about twenty seconds after letting go of the switch. In the right hands, it will cut a line level and square. And believe me when I say it's seen some serious use, in many separate hands.
I've since bought about every brand and size since then, and have never been as satisfied as I was with that one. Even the 8 1/4" saw, supposedly the same saw but larger, and about fifteen years newer, hasn't impressed me as much as the first one. Cutting a level line with that one has never come to be second nature like the first. (In all fairness, I personally haven't done the amount of actual corporeal work as I did in those early years, thank God). I am still able to cut a very level cut with the traditional one though.
That saw wasn't a worm drive saw. That singular style of saw seems to lend themselves to cutting a level line rather easily, and have plentifulness of power. This style is the first selection of many expert contractors, due to there ruggedness. I have, and use this type of saw as well, but I limit it's use to very abusive situations. They are made to take it.
I've bought saws from manufacturers, that were reputed to be very high quality, and were made by the very same habitancy who made some serious equipment, that performed extremely well. After using them for a combine weeks, I just gave them away. Some saws are not designed for the user, but for the ease of manufacture. No thank you very much!
Sometimes I swear that the engineers have never held, used, or researched the very tool they were designing! And the surprising part is they well make it to the market. You'd think that somewhere along the line, someone would have said, "this is a piece of junk", and sent the engineer back to school, or at the very least, back to the drawing board. But no!
One of the newer brands on the shop in the Usa, is Festool. While it has it's limitations for construction, for cabinet manufacture it's great. With the extendable, non slip, track system, cabinet ability cuts are simple. Even mitering cabinet sides on a job site are no problem. And with the dust variety principles hooked up to it, it's hard to beat. I did notice new users have a bit of trouble getting used to it having a retractable blade system. This lead them to well having a kick back, and cutting the aluminum guide. This seems especially true for left handed users. And for those with two left hands, forget it.
Bottom line in choosing a saw is first deciding what type of work it will be used for most often. If you're going to be cutting 2" x 4" lumber, forget the Festool. It's just not worth destroying a good saw for that. Also, stay away from the .99 saws, unless your need a curved cut, because level is out of the question. Anytime you can watch the shaft slide in and out While a cut, you have a problem.
Look for a saw with a 15 amp motor, and try to move the shaft in and out prior to buying it. (Unplugged of course). If possible, test it out. Some saws go out of there way to blow the saw dust in your eyes. Having a shoe that won't bend or break is a big plus, and a notch where the blade will well cut is pretty handy. (Although, I rarely use them. I like to see where I'm cutting, so I look at the blade). And By All Means, use security glasses.
Following these basic guidelines will get you a saw that you'll be able to count on for years to come.
Circular Saws Reviews
selecting a Circular Saw