It is well-known that SF gear used very good parts quality and build was excellent. However, I personally had some issues with their Line 1 preamp and on one occasion, with a Power 2 amplifier.
Overall though, there is much to like about SF gear, I would own it again in an instant although more recent gear sound more transparent and resolving in my opinion. I recently compared an Ayon Orion integrated to a Line 2 - Power 2 SF combo - The SF had it on power, but everything else sounded much more refined on the Orion.