Saxman is correct. Compare horsepower and weight, that's all that really matters. Very few people will ever wear any chainsaw out. Sure, they'll burn them up, crush them with their car or drop them from trees, but wear them out? Hardly. If you can wield an extra .7 lbs or so, save your money and buy a mid-range saw. All Stihl saws spin around the same dang rpm, check the specs. I'm not impressed with "pro" saws in dollars per pound / hp versus mid-range saws, but then again, I'm not in a race to cut a log.
A similar weight and hp saw in the mid-range user versus "pro" user saw is a draw, except one is supposedly able to last longer and is built better. I ask how? Better pistons? Don't believe so. Better ignition module? Don't think so. Better carb? Aren't they mostly all Walbros? Better crank shafts, rings and seals? Nope. Spark plugs better? Nope, NGK or Bosch. Pistons better? Doubt it. Where's the real difference????
I believe a 4 hp saw of any lineage will perform as well as a similarly powered "pro" saw, provided they are both operated / designed within the same rpm range and are using similar chain types.
Am I missing something here? Except for how the "engine" and other extraneous outsourced parts are housed, what's the costly difference that gives the "pro" saws such value? Seems to me the "pro" saws are more prone to develope crank seal leaks due to the manner in which they are seated in the saw housing. The clam shell design appears to eliminate that.
I'm pretty mechanically inclined. I haven't rebuilt any saws yet, but I have absorbed a lot of information and have viewed countless videos showing saw rebuilding step-by-step on youtube. May end up buying a used project "pro" saw for giggles.
I don't saw for a living, but I'm fairly certain most here don't either, based on how often during the day / night / week they post.