Hi Gordie
I agree that mediation may not be required if you still have a reasonable relationship with your stbx. It can be expensive and not essential if you can both agree to a fair custody arrangement.
I get to see my kids alot more than most people, but I am finding that although I love my girls and love to see them, my ex W tries to dump them on me when ever she sees fit. Not saying you should not be thankful, just that a you need to be able to make plans of your own from time to time. The other problem arises if and when the time comes that you or your ex wish to date again...the rules can suddenly change and arrangements need to be in place so that things remain fair. I am still hopeful of reconciliation some day so maybe I am more tolerant. Should that not happen, I know the situation could become more difficult.

Things do improve albeit slowly. I wish you luck.