My gaming group is big into co-op games. We like Pandemic, Firefighting Diceroll Extreme (now with dog), Defenders of the Realm, and Ghost Stories/Yggdrasil. We also are very fond of games like Arabian Nights.
So that said, is there any reason we shouldn't pick up Eldritch Horror?
A couple people in our group are wary of the length of it (but we play games like Arabian Nights and Myth no problem...) and none of us really wanted to play Arkham, but still loved the idea of it.
I've never played Arkham Horror, but I've had a few runs at Eldritch Horror. If you can get in to the theme it can be a lot of fun. A lot of the mechanics, such as condition cards and asset use/collection really help to bring out the theme but there is quite a lot of randomness. The randomness is what makes the story interesting and unique, however it comes at the cost of elegant mechanics.
Pandemic, for example, has very little randomness by comparison. Because of this, you can reliably plan and execute strategies that involve teamwork and coordination. Eldritch has a bit of this, but oftentimes random events can screw you, or render previous planning pointless. Oftentimes you will find yourself having discussions about where people should go to manage the crises that are constantly popping up around the world, but sometimes fate intervenes and all the planning in the world wouldn't have saved you.
If you think that your group could get interested in the theme and would enjoy reading the flavour text then I think that you will have a great time. If you think that they would rather be more in control of their fate with strategic decision-making, then perhaps look elsewhere.
Also, though I would probably rate it higher than they do, check out the Shut Up and Sit Down Review, which is an excellent overview.