4 attacks gives you better damage output due to] enemies healing, but three attacks with passives isn't bad. It's not worth splitting hairs over unless you're going for a speed run or trying to get through GR and Kam quickly.
The problem with 4 attacks is that I can barely get to the 4th attack before the first attack ring is ready to be used again. 4 attacks just adds to trouble of pushing an extra key every cycle.
i wonder if it's any easier for left-handed people