Overrated how? Before the player break, he's probably been the highest rated primary AWPer up there with the big three of s1mple, Zywoo, and dev1ce (who's relatively not been as great this year as the former two). Syrson was leading some events in opening kill rating (high success rate and attempts). His impact rating has consistently been the highest in BiG too. Compare him to the likes of Kennys and Broky, the stats would say that those two are relatively overrated by the community. His LAN sample size with BiG is pretty small and it wasn't against much tougher competition, but he was still rated 2nd highest on the team while scoring the highest impact rating. I agree we need to see him more in LAN conditions to be able to judge him well, but as it is right now he's doing great online like the rest of BiG or teams like Heroic.
If anything, right after the break it's BiG as a collective who has been inconsistent and underperforming, especially Tabsen, which is pretty evident in their results (and yes including Xantares, not sure if you're counting him in 'every german player'). Last event Syrson was relatively poor, but prior to that he was always leading BiG.