Yay, I love Alex Monroe. I strongly suggest going to see them in real life it will help you decide.
I love, love, love this one.
Another option is to look at some vintage rings, I know Bath is good for antique jewellery but don't know where you are. A good friend has a non-traditional engagement ring that is a 30s dress ring and I do covet it. Sure some MN people might be able to recommend a good place near to where you are.
Tiny butterfly twig will catch on things imo and you'll find it annoying to wear everyday, imagine it catching on e.g. hair, knitwear/clothing, bags all the time. Double Lily might be similar but that's why it would be good to try. What you would put up with for an occasional wear ring is different to what you would cope with everyday - same with e.g. a massive diamond, I think it would get in my way quite a bit.
I really like the posy twist and the meadowgrass too.