Seasonal adjustment, any major organisation uses STL?

Question

X12 is used by the US government and TRAMO-SEATS by EU governments. Is there any major organisation that uses STL?

Since X12 is more widely known than STL, I would like some supporting arguments that STL is as good as X12, apart from some numerical experiments I can run myself.

Answer 1

I do not have argument supporting STL, only one for X12.

In X12 there are usually non-linear filters removing outliers before other procedures are done. This is thought to improve seasonal adjustment process.