It's not about "alternative feed readers" but about "alternative feed readers with subfolders support", so my initial question requires experience with feed readers, not just "list me some RSS readers please".  :)

GreatNews fails to import some of my feeds, "unknown format", WTF?  :huh:
Oh, and it does not support subfolders, so: Bye, GreatNews.

Google will never know what I like to read.

And it doesn't support subfolders.

During the past few years I have tested quite a lot of RSS reader software. Online RSS readers are ridiculous, I use RSS because I don't want to visit a website for everything.

Currently I am stuck to RSSOwl for one simple reason:
I am stuck to subfolders.  :D

I have quite many RSS feeds (> 100) in my list, and I sorted them into subfolders just because I had the chance to do so. Now RSSOwl is not really resource-friendly (Java...), so I wonder if there is a decent alternative with subfolders support.

FeedDemon does not.  :(