My Mil was probably the nicest person I have ever met.
She gave birth to my DH (for a start).
Long story short; meet the Mother and then ascertain the level of respect/regard she is held within the family; and you can judge any by that mark.
So NO. My MIL was not awful dreadful or in any way horrid.
She did a bloody good job. I'm thankful that I married her Son.
She passed away in 2006; and there's not a day that I don't miss Her.