Neither. There are atheists, who claim others beliefs are being forced down their throats, yet they go and force their belief(adamant nonbelief) on people who may disagree. There are some religious people, who essentially do the same.
Then there is over half, that respect that others have other beliefs. They may try to change someone else beliefs, but are not overbearing, and forceful.(ex christians who have diologues, to try to convert someone, because they want that someone to be saved. They dont force it, and just engage in conversations, not being to preachy)
Then there are those, who are so stuck up in their ways that they see only their way as being the exact and only way.
(ex. some groups of Christians, will think their church, is the only path to heaven.)
Basically the point is, that nearly every religion, (and atheism) is full of essentially the same groups of people.(ex just because you are a "Christian" doesnt mean you are a good person. And just because you are a atheist, doesnt mean you are a bad person. Lets say 70% of man was good, and 30% of man was bad. IN general, that ratio, will go to all groups of people, and remain the same.(humna nature happens regardless of beliefs)
But to answer your thread. Generally, i have found from MY PERSONAL EXPERIANCE, that religious people, are generally more open to others beliefs. The theists, generally are the most open to others beliefs. I know many atheists, who get enraged, if their friend prays or something. They just get so offended. (which is really irronic, because a true atheist would just ignore it, because they believe the person is just talking to a imaginary friend.)
Generally religions, are more open to others beliefs(as in cooexisting, and not getting offended and stuff) than non religious people. Now there are plenty of religious people, who are so hardcore in their beliefs, that they do not respect other peoples beliefs.
Religious, is more open to generally others, while non religious people, are only more open to others lifestyles(see abortion and lgbt) Religious are less open to argueably moral issues, but more open to others beliefs.
Theists(people who believe in a creator/s, but dont choose any religion, or worship etc) are the most open of all. Generally most theists, i know, are more open to morale issues, and open to others beliefs.
If you want proof that atheists are the least open in general beliefs, then just look at all the people who get so offended, that they ban prayer in schools.(non manditory prayer as well. If you dont believe something, you dont have to say it)
But being open to someones beliefs, DOES NOT MEAN, you have to agree with them, or even think their beliefs is right.
For example, I think that lgbt peoples lifestyles are wrong, but i will not treat them any less respectfully, or with less dignity than a straight person. I may dislike their lifestyle, but i will not go and dislike them.I may choose not to hang out with them, but i wont treat them any different than anyone else. I will not go over to one of their couples house, and try to force my belief on them.
Im sorry if im not coherent(as im getting tired, and ready to go to bed.) but if I articulated my point well enough, a logical, neutral person should be able to agree with me.