I want to use my grandmothers name as a middle, but it doesn’t flow as well as say a filler m.n. what do you think is more important–flow or meaning?
I think whatever is most important to you. If it’s important to honor your grandmother then don’t worry about the flow.
In our everyday lives how much do we really use our middle names!?
Definitely meaning. I always pick names for their meaning, and if it flows-- then all the better.
First meaning, then flow.
Meaning is more important to me.
I think meaning is more important than flow.
Meaning important to me.
Another vote for meaning. 
Flow is important too, but meaning comes first.
Flow is more important - a nice meaning is just a bonus for me. I don’t believe a person “becomes” the meaning of their name.
Meaning.
Sound might trump meaning (alliteration, rhyming), but not flow.
Meaning, without a doubt.
Meaning is more important to me.
I would say meaning. Especially for middle names
Meaning 100%!!! After saying the name for a couple of years you’ll get used to it. Meaning is far more important. Plus, if its in the middle name spot, it won’t be used very often except on legal documents.
Meaning unless the flow is absolutely horrible like [name]Malia[/name] [name]Leah[/name] or something repetitive.
I would say meaning as in honouring somebody who was really important to you, would triumph over flow, but if it was that important a name to you then surely you would be able to find another that flows better. Unless of course the issue is with it flowing badly with your last name, and then unless it outright rhymes or something, then flow can take the backseat.
Have you thought about making it a double middle name so that it flows better? I think meaning outweighs flow, but just a suggestion in case flow is bugging you.
Meaning always trumps flow for me. 
Flow. Meanings are a nice bonus.
If you want to honor your grandmother but you don’t think it flows well, you could always use her middle name, last name, maiden name, something that reminds you of her, etc.