My vivi nova tasted horrible for about 3 days after I started using it, but after that it was good. I like the vivi nova and the stardust style clearos (standard resistance) the best, but I just got a carto tank and I think it's converted me from clearos. My first stardust clearo lasted about a month with pretty heavy
vaping (I kept my all day
juice in it). My vivi is still going strong with the 2.4ohm head that came on it, and I've had it about a month as well. I had a Kanger T3 and hated it.
Keep
vaping the vivi and adjust your voltage some and see if it tastes better after a while. Some clearos, from my limited experience, seem to need to be broken in a bit before they start working well. I would suggest trying the stardust style clearos, and maybe a few others to see what you like best. I would only get one of each to begin with, though, in case you don't like them. It's really personal preference and you probably won't know what you'll like best until you've tried a few things.