Many chassidussim use their own nuschaot, typically based on Nusach haAri or the so-called Nusach Sefard. For example, Sudilkover Chassidim use their own variant, as discussed in this blog post.
What is are some of the variants in tefillah used in Satmar (relative to a "standard" Nusach Sefard, if it exists)?