Did anyone have a good experience using their mom (grandma-to-be) in lieu of a doula?

I have a great relationship with my mom, we planned my wedding together with no problems and we are very like-minded. I only get two people in the labor room and when I mentioned that I'd met a doula I liked, my mom seemed disappointed.

I was considering a doula since I'm using an OB/hospital but would like to try for a natural birth, plus it's my first baby. I am interested in having someone there to navigate the hospital for us and help me figure out what interventions I really need and which ones I may not (something I'm worried about). Also, I like the idea of having a part of my "team" there the whole time, no matter what nurses are on staff that day and since my dr probably won't show up till the end.

Anyway, on the one hand I would like my mom to be there--she does comfort me a lot, she had three kids herself and I think she would be great at making friends with hospital staff, etc. Plus a doula is an extra expense we can barely afford. But I'm worried about losing someone with some more knowledge about medical procedures that can help me decide what I need. I'd like to labor at home as much as possible, and I wonder if a doula will have a better idea of when I need to go the hospital for real. I wonder if it's too much pressure on my mom to help me make those kinds of calls on her own.

DH is wary of doulas (too "hippy" and expensive for him) but he's also a little worried my mom will take over his job (he likes her, btw, but a doula may be more aware of including him). He keeps saying whatever I want, but that's not helpful!

Anyone have any advice on this? I am having a hard time figuring out what I want--I love the idea of a doula but I can't shake the feeling that I'm going to want my mom there!