I've come back to the game for the start of the current season, been playing a lot, and I haven't faced a single Syndicate opponent. Not one in over a week playing 3-ish hours every day.
SY had 2 T1 decks last season. It still has completely boring/broken/annoying mechanics that repulses me every time I see it against me. Still hadn't played with it and I am not intending to play with it in the near, nor the far future.
Syndicate is too limited and it's so one dimensional, an absolute bore to play with or against and very deal dependent. Philipa, Borsini, Professor, Defender, Witch Hunter, Moreelse, etc., all become auto include The Strategem is probably weakest of all of them too.
Syndicate is still quite strong if played well.
Arena wouldn't be so messed up as it is now.