Eden Eternal has better vanity items, but I personally didn't like how the characters looked. I didn't play long enough to make any mention about the grinding in EE, but grinding in GF is quite okay. If you field map grind, you can go half zombie mode and just press 2-3 buttons and auto tab.
GF is a good game, our version is less active, so finding someone to grind with will prolly be ur biggest problem. As the above poster said, you should just try both and see which one you like better. Good luck. \o/