delta dental vs FEP BLUE?! GEHA?! Humana?

they both have about the same coverage and cost about the same per month. my question is for the customers who have or have had these companies as a dental insurance. did you like them? hate them? love them? i need to have some major work done and these are my best option. except all of the reviews i can find online all the companies are one star. and they seem to not want to pay ANYTHING. have any particular problems with one company? please let me know of your opinions on these dental companies! thanks