Woody, there's a lot of stuff I can say that's just going to come out as a generality, so here goes.... All of the manufacturers have had to "step up to the plate" to meet the four-fold chainsaw dilemma: Weight, Power, Reliability, and cost - you can only choose three of the four! The really high end saws are light, powerful and reliable, but not cheap. These are the "Pro" Stihl, Husqvarna, and some Makita (Dolmar) and Echo. The mid grade saws are very reliable but sometimes sacrifice a little power or weight to help keep the cost down. Same brands as listed before, but the "lower cost" model line. The Poulan 5020AV is the cheapest of these. The low grade saws are typically light and cheap - - and powerful "enough" on the ones that are reliable (Like my CS2245 and Husq 445).... and the ones that are cheap and perform with really good power have bad reliability (RedMax, Cub Cadet, Remington - all made in China/Taiwan) Enough said about that! You asked specifically about RPM, and 20 years ago it was still true - The Husq's screamed and the Stihls growled. Because it's become SUCH a competition to build a saw that's light, powerful and reliable - the differences between them have blurred a LOT. They pretty much all "tach out" around 12,000 RPM now. The machining tolerances and materials have advanced so much over the years that there's not so many differences between them anymore except for cost... and you get what you pay for (for the most part). When it comes to cost, many folks can't justify the cost of "Pro" grade saws. Like the 50cc-55cc range (most popular for firewood cutters)... you can get a Poulan 5020 for $139 (as a "refurb"), or a new Husq 455 or Jonsrd 2255 or Stihl MS271 all for about $350-$400 or so. I think the Echos are a little less. "Pro" models in this size range seem to run closer to $800 anymore. Another one of the biggest reasons saws seem so similar anymore is for emissions. Yes, the good ol' EPA (gotta love 'em ) has been trying to DESTROY all chainsaw manufacturers for years now!! (and all 2 strokes). Sooo, you'll hear new buzzwords like "Strato-Charged" and such. All of the main saw makers are now trying to make saws that will run on leaner mixtures (for emissions) without burning the pistons down. It's been a big challenge to make strato-charging work, but it needs RPM's to work. sooooo.... pretty much ALL "new" saws that meet "new" emissions regs... ...are now all high-RPM models.