Wick tanks, at least where the Vivi's are concerned, darken the color of your juice as you work your way through a tank's worth. It's clearly visible if you decide to top off half way through; you can actually see the color variation between what was there and what has been just added. For me, I was vaping Alice in Vapeland's White Rabbit - normally amber in color, turns a darker brown when I hit the half full/empty point. This hasn't happened to me while vaping HHV's Cinful Pear, however Cinful Pear is pretty much a clear juice to begin with.
Cartos are harder to fill, but the juice color remains consistent throughout.
Wick tanks have to be tipped to keep wet (as the tank gets lower), cartos have to be dry pulled on to keep the polyfill moist, or you'll get a dry burn. Each have their pro's and cons. With cartos, you can hear the juice vaping...with wick tanks, it's pretty much silent.
100vg juices may be difficult for cartos due to their thicker viscosity. No problem however using 100vg in a Vivi tank.
As far as throat hit is concerned, I think that has more to due with juice ratio and voltage setting.