To be honest with you I really like the monogram canvas, so if it would be me I'll go for the monogram one. But you have to decide after all that's just my opinion. If you could go to one of LV shops and try them both on you I think is also a good idea.
I also have a speedy 40 in monogram, but i am very undecided, it goes to end that I take both bags
However I have another passion, the purses of balenciaga, my mother says that i'm like a drug addict ))