The Typhoon-vs-Su-35 quote was someone at RUSI; I could look the name up. The analysis was weighed heavily on the idea that the Su-35 has better manoeuvrability, and particularly a radar with high transmit power, very good EW (within publicly available information) and missile fit. In a (plausible) scenario where rules-of-engagement required visual identification (Baltic air policing was mentioned) a visual-range engagement was felt to be much in favour of the Russian aircraft. At longer ranges, AMRAAM was felt to be showing its age in the context of Su-35 EW capability.