My mom always has told me - if the good times outweigh the bad - stick to it. Sometimes this is questionalbe - the bad times seem to be very strong.
As you mentioned you now have children - and I have realized in the past few years that unless the marriage is physically abusive - if you leave now - chances are you will swap one set of problems for another set. You won't like everything about one or the other if you remarry.
The Lord will bless your marriage in many ways and especially you personally if you hang in there - doesn't always seem so. But he promises us.
The benefit once you have children - is knowing you have worked to keep their family as a unit. One day you may have grandchildren and you will be able to look at them together (you and your husband can look in awe together at what you two started and have that peace of mind that you remained steadfast to a promise you made to each other and to our Father in Heaven). The grandchildren are the fruit of the spirit. I haven't had more joy than in sharing my grandchild and watching our children grow together.
I divorced my twins daddy when they were 1 1/2 years old. I remarried when they were 4 years old. My husband and I of 22 years have had many struggles - I married him based on a prayer - and have many times wondered??? about leaving. But, I have stuck with him and we have two children, it isn't easy but I can see the difference of the children that grew up with their daddy in the home and the one's who didn't. It does make a difference, even when we don't like each other very much. May the Lord bless you and keep you. When you are going through a rough time - a prayer that I pray is: Dear Lord help me to be the wife and mother you want me to be, and my husband the father and husband you want him to be - your will in this marriage. Amen. I have found that with this prayer our lives are better.