After a solid month of continual use I decided to offer my personal review of them. They came with factory chains and I really noticed the difference in performance between them and the new pro chains I'm running.
The 0.36 25 inch bar uses a chain that has teeth that cut a larger kerf than the 0.50. And this is coming from my own experience with them. I certainly don't know everything but this is what I know so far.
The 291 is 55.5 cc that they rounded off to 56 cc, and is 3.8 hp. The 271 is 50.5 cc's and is at 3.9 HP, which is more than the 56 cc Home owner version 291.
The 391 is 64 cc and has 4.4 bhp. They're heavier than the pro versions. And don't have the Intelligent carburetors like the pro saws. But are perfect for the non-professional home owner like me; and farmers, power utility workers etc.
The 291 has a price tag of $499, and I paid $730 for the 391, with tax. Obviously the prices vary so it definitely PAYS to search around. I was about to buy the 391 for almost $800 until I found a company selling it for $679.
Luckily a friend who was a Stihl and Husqvarna technician gave me a couple micro screwdrivers made by Stihl if I ever needed them. Which meant I carried them in my pocket and still do just in case. Ama*on has them also.
The 20" bars that come with both are definitely light weight and have a nice plunge narrow tip design.
My suggestion is don't rate the performance of the saw based on the factory chain that comes with it. If you're not skilled with a file it won't perform properly. The pro chains seem to cut faster but are more dangerous for the inexperienced user.
So far I've found that the Husqvarna XP+ chain appears to be the closest to pro chains in terms of cutting speed. But the Oregon Pro and Stihl Pro chains cut faster because there's no double raker on them and the teeth are spaced further apart. I'm an experienced user but am following and researching how the professional arborists and loggers use their saws and deal with more tips and techniques for really challenging applications.
"Buckin Billy Ray Smith" and "Guilty of Treeson" are the two channels I watch most as they seem to cover everything anyone would ever run into. And have different outlooks and techniques between them. They're awesome guys that absolutely know, and show exactly what they're talking about. There is a difference between a veteran logger and younger tree fellers, IMO. Both channels are great in their own right.
If I made errors please inform me. Any pros out there feel free to add some tips for us "Professional Home Owner's" and any other knowledge, obscure or not, that you might want to mention ! All of it helps the field of forestry management/conservation and anyone else who's developing/managing land while watching and learning !