For some reason common assembly changed to feudal for all CO leaders on map (all their vassals remained CO) soon after rebellion against votgs. Happened in 3 games in, but when I tried to reproduce this bug, it doesn`t happened, only 1 my vassal changed from CO to feudal.
Is that a bug or some kind of mechanics unknown for me?
Upd: Is goverment type dictated by estate trait of character?
Upd2:happened again, even before rebbelion
Upd3: Got it. It changes govement form on save-load. All you need is to start game, save it even unpausing, load it and all Co changed to feudal.
Also:
Trade route bonuses looks way to huge - my 9 provinced Uri gives same amount money as huge Milan, and this with only one tradepost out of 5 possible. One usual city gives 25 gold, one on a trade route gives 75, giving me in vassal tax 25 - just like whole city in domain! One traid post gives me 145 coins (even with 40% trade zone bonus), when whole milan duke income is 405, Schvaben -215, Burgundy - 140.

CO looks totaly overpovered - you get all your vassals levy as allies and they still paying you taxes, which u can set up to 60% Only downside is elections every two years, which also gives you 200 prestige (3000-6000 during lifetime of character - huge amount).