I've had fairly decent luck with Husqvarna, though it really depends on the model. Given you're looking for a 20", but as anecdote I have a 142 which is an acceptable 16" saw, but it's a little doggy compared to some other models. That said, it's managed to do 100% of everything I asked of it including cutting up a willow that was well over 30" DBH, but a pro would probably toss it for something larger and with more power. I'm not recommending a 142 as it's both smaller than what you're after and not exactly their best performer, but it serves to demonstrate that there's a lot of variables to consider. I can make a doggy little saw do my occasional tasks, I don't mind spending a little more time here and there chewing through something bigger than my saw was designed for because I do so very rarely these days, others might feel differently. How often do you expect to use it and what's the DBH of the largest tree you expect to deal with?
When I still had my cabin and woods, I had a STIHL MS460, which was a very nice saw, but it sold with the property as I had no real use for it when I moved. I bought it used, but it was a fantastic saw and served me well in transforming a neglected woodland into prime woodland estate.
If you're like the typical homeowner with a small woodlot, get a decent saw of most any brand and it'll serve you well if you maintain it.
Some will chuckle at this, but my go-to saw is typically my Silky Sugoi pruning saw. It's often faster than the chainsaw for quick jobs removing a few limbs under 9".