Television budgets and time constraints put a strain on believable CGI made for the small screen. In my opinion, television audiences see a certain level cheezy effects according to how much money and effort is devoted per episode (e.g. larger episode budgets usually equal better CGI, smaller budgets usually equal less quality CGI).
Storylines and acting will play major roles in how well this series will be received. However, visuals will play a major part in its believability if ABC/Marvel stays true to the characters. This is not The CW or The SYFY Channel. It is one of the four major broadcast networks with the deep pockets to invest in movie-type quality CGI.
It would be in ABC's best interest for the CGI effort to be a tier better than what has been seen on Marvel's Agents Of Shield thus far, whose CGI work ranks as solid B+ quality in my book. Even though that grade is better than, say, the ones I have for The CW superhero series lineup, the visuals could be better. That would work in the favor of translating the powers and abilities of The Inhumans much better for audiences.