I'm on the hunt for a sling, what has worked well for you?

I take all the sling swivels off of my FALs.

Blue Force Gear VCAS is my choice for my XCR, though. I'd be happy with one on an FAL.

BFG padded Vickers sling in OD green.

https://tabgear.configio.com/shoppingcart.aspx?com=detailview&iid=894&source=search

But then, I only use the sling when doing 5k/10k/20k run and guns.

Since the FAL isn't real happy being shot "slung up" with a tight sling, any sling is really more of a carrying strap.
For that purpose, the 1908 pattern web slings (used on SMLE, No.4/5 rifles and the L1A1) are cheap, readily available, easily adjustable, and come in different colors (or colours).

I'm using a BFG VCAS with the quick release mounted to the front end to allow it to serve as an extension (I'd rather have a simple strap) to allow me to use the sling as a shooting aid.  To facilitate the latter, and for other reasons, I have a handguard mounted swivel.  I intend to mount a sling swivel on the right side of the buttstock, which at this point is my preferred position for right-handed use of a rifle with a tactical sling, as I like it better for shoulder transitions.  The standard bottom swivel work in a pinch, but under some conditions the rifle will, of course, want to flip upside down.

Accept no substitutes...

https://www.blueforcegear.com/vickers-sling

The correct Austrian sling for my StG 58's. SAR 48 uses the Enfield pattern sling that came with it.