I used to have a Speedy 35 in Mono, but it was a decade old, so I sold it to buy a new one, but went to a 30, and bought DE. I just got a Mono Artsy a couple weeks ago, and I am in love. I have mostly Monogram (also a Neverfull and Favorite) so the Speedy is my only DE item. I know a lot of people get all the prints in the same bag, and I think that works for them because the style is timeless. I would ask yourself if the reason why you have all three prints because you just love the Speedy so much and it's your most used bag, or has this feeling changed, and you can see yourself using a new bag more than one you already own? It seems like this is the case.
If you aren't using it, buy something that you will use and love. I am about the same height as you, but I'm a size 6. I don't think the bag is too big, and I love its size. I also don't think it's uncomfortable, and you're right...its soooo beautiful! I personally don't use this as a shoulder bag. When I bought it the SA told me to be careful if I did wear it as a shoulder bag because it's not meant to be worn that way, and people's deodorant caused cracking on the canvas from rubbing against the bag. I think the Artsy looks best carried in the crook of your arm or handheld. If you wanted a real hobo style bag, the Delightful seems to be made for shoulder carry, and has a longer drop from your armpit.
I would love to own the Artsy in DA and paired with its shape, the overall look would be so feminine. I would go for the Artsy! They have improved the canvas and braided handle, so I think it's a great time to try this bag. I waited several years to purchase because it had issues in the past. Happy they are resolved.