On transients it is moderately restrictive. On ephemerals it is murderous - nobody has access to reasonable numbers of first round strikes or maneuvers and getting reasonable numbers of any basic combat card requires serious contortions. Second, card limits strongly favor certain disciplines. In Jyhad every card is supposed to be basically unique, but in some cases a variety of cards have similar effects. In order to use a discipline reliably, you must find one with lots of duplicate cards, prefereably transients or permanents.
Vote tends to get hurt, as few votes have near-duplicates.
Combat gets clobbered, because most combat cards are ephemeral. Under 4-card, Malkavians rule. Tremere still work pretty well too. They get shoehorned into intercept 2nd round combat, but both Dominate and Auspex still work. Gangrel are playable, but have a hard time.