Every Echo that I've seen, they all have adjustable oilers and the 3 I own have no oiling issues whatsoever. Of course I use real bar oil and not used motor oil either.
An Echo is a good saw but a Stihl runs faster and therefore has mare chain speed and cuts faster. As for the other comments, I’m not sure I would worry about having a 36” bar for occasional use either.
And yet, it has a 5 year warranty and is plenty capable for my large Burr Oakes. Not the fastest, not the lightest, but a fine saw for me. Expensive I’ll grant you, but I'm happy with it. BTW, the oiler has no issues with a 32” Bar.
I love Echo saws. I own a few of them and enjoy each one. Some of the models are better than Stihl or Husky and some of them aren't. But one thing is for sure, Echo's warranty flat out sucks. They give you a 5 year warranty but will do absolutely anything to deny a warranty claim, and even if they do approve a claim, you're still out of pocket for their warranty fee. I don't buy any saw based off it's warranty.
With the exception of my compact tractor, all my yard equipment is Echo. Other than collectors, I think many will choose their favorite manufacturer if they're happy with their first purchase. I do believe the STIHL owners are the most dedicated.
Personally I am not a Husky fan either.. Even though my 24" bar and chain would fit any of the models you listed, but would have to go with the 3120XP due to my 36" being .404 if I wanted to keep using my current bar and chain.
I have two Husqvarna pro-level saws and a Jonsered "pro-ish" saw (pro construction, magnesium case, but not billed as a pro saw). I've been very happy with all of them. I'm not particularly brand loyal. Frankly, I just ignore the folks who say things like "brand X, all day" - implying that anything from brand X is better than anything from brand Y or Z for everyone's needs. I'd buy a Stihl saw if I liked one in a size range I was looking for. Husqvarna used to have a several great servicing dealers in my area, but they have retired or passed away over the years. There is still one decent Stihl servicing dealer in the area (a tractor dealership who also takes their Stihl product line seriously). I'd also consider Echo, if only they had a good servicing dealer in my area.