The Banana was a struggle for me on bikes with racks and fenders. My idea was to use one in place of a bigger saddlebag on no-load rides, but that position put the toggle right on top of the racks on the smaller frames I ride so it was a hassle fishing for it. Also I tend to agree with Leah that it's kinda funky looking.
The XS was just too small for me, especially for the price. It's barely more than a basic wedge bag and I've never been able to pull off that level of minimalism.
The Small Saddlesack is fabulous and it's too bad Grant/Riv had to make a bigger replacement so it would sell. It carries all the basics, plus room for a quick 7-Eleven run, without being This Huge Thing on the bike that needs a support. You will get thigh rub though, it sits pretty snug up against the saddle and post. I don't mind it but YRMV.
I’m looking to buy either a Banana Sack or Small Saddle Bag (also the Riv one). I’d like to read some opinions of both. Thanks!