This document discusses using EMF-IncQuery as a query language in Sirius for defining viewpoints over EMF models. It provides an overview of Sirius and EMF-IncQuery, demonstrates defining queries in different languages, and evaluates performance of incremental recalculation. Experimental results show IncQuery queries have blazing fast reaction times for incremental updates even for large models. The approach is proven in a motivating EU project but still requires expertise in both Sirius and IncQuery and could be enhanced with Obeo's help.