i`m looking to get a new saw in the spring, wondering how much of a diff is there in cutting speed and power between say a 3.0 to 3.1 hp or 3.1 to 3.3 hp saw, is it that noticable? And has any ever measured the hp increase when a muffler is opened up on a say for example a husky 359- stock 3.9hp to ? maybe 4.0-4.1hp just curious. maybe a 5-10% increase?