Well, maybe the drag, since you have two Trims and have another Birkin coming? I'd definitely keep the Evelyne. I also want one for traveling - wear Evelyne across the body with wallet and passport and carry the Birkin with other items (books, pashmina) on the plane.
The Trim is really well designed and is my "throw around" Hermes - although I've used it steadily for almost 3 years and it looks new! I have a 31 and could also use a 35 in another color...