There are many different types of saws in the world. My most favorite would have to be the chainsaw. I purchased the worst chainsaw I've ever used at www.sears.com. Now, whenever I buy a chainsaw I always ask if I can take it outside and make a test run. The best thing to look for when you test is to make sure there isn't any smoke. The next thing I check is how many revolutions per minute. I
. check the rpm by putting a piece of tape on the side and watching how fast it rotates to the starting point. I've seen enough chainsaws to know the difference between a really powerfull saw and a weak one.