My mother and my mother-in-law were both kind, loving, caring, people - but, of course, my mother was my mother, which was that unique kind of relationship kids have with their own mothers. My husband's mother was someone I cared very much about, got along with, and appreciated in so many ways (especially for the kind of grandmother she was to my kids and their cousins).
When all is said and done, though; yes, I saw a big difference between how I felt about my mother versus how I felt about my mother-in-law.
(Am I the only one on here who liked both my mother and my mother-in-law? It's sure looking that way to me right now. :) )