VCV captures the natural transitions you make when you move from vowel to consonant-vowel.
In that aspect, it is more capable of being "realistic" and "smoother" than CV.
But CV can also sound just as nice if you have a good oto that replicates these transitions well enough.
A good CV is still better than sloppy VCV. Great VCV can't really be rivaled by good CV in return.
VCV is not that much more difficult that CV. It just takes a bit longer, and recording can be sort of tedious since it's in strings and as such you need to set a pitch and tempo guide.
Using them is a matter of how good the oto is. A good CV will be easy to use, and so will a good VCV. there are like 4 CV>VCV plugins and they always work file for me.
Just some things to think about.