In terms of design, I think the neonoe has a nicer silhouette than iena, but there are some things you have to consider.
Neonoe is light but if you stuff it and it gets heavy, the straps will dig into your shoulders. I've gotten sore shoulders from making it too heavy. Neonoe is also bulkier than iena. If you live or work in an area that has a lot of people, like a metropolitan area, it can really knock into someone, especially on public transportation, like the subway. Neonoe is open on the top. If it rains, the contents of your bag will not be protected from the rain. However, since neonoe uses treated leather for the straps and detailing, rain will not cause water stains. The divider in neonoe is also not fixed to the bottom. Pouches, keys, phone, whatever you put into the bag can slide under the divider. If my bag is full, I sometimes have to dig around because the thing I'm looking for managed to slide under the divider, under everything else.
Iena can fit a lot more than neonoe and is also light. Iena is soft so it molds to your body more, you can really hold it close to you in crowded places. It can be easily flattened and stored too. It has pockets on the inside... I think 3? Iena also has a d-ring, which is very convenient if you don't want to dig around for your wallet or keys. There is also a zippered pocket on the outside of the bag, which is nice to put your phone in, or something else you want to readily access. You can also zipper iena shut and it comes with a lock and keys. This offers more protection than neonoe, especially if you plan to travel a lot with your bag. Since you can also zipper iena, you don't have to worry about your things getting wet, if you get caught in the rain. Iena in DA is vachetta leather though, so water will stain it. DE is fine since it's treated leather. If you really like the idea of a crossbody, go to your closest boutique and request to see iena with a strap. I'm thinking one of the straps I linked would work.
Ebene, 16 mm adjustable strap https://us.louisvuitton.com/eng-us/products/adjustable-shoulder-strap-16-mm-ebene-epi-leather-000327
Vachetta, 16 mm adjustable strap https://us.louisvuitton.com/eng-us/products/adjustable-shoulder-strap-16-mm-vvn-vvn-004672
Vachetta, 12 mm adjustable strap https://us.louisvuitton.com/eng-us/products/adjustable-shoulder-strap-12-mm-vvn-vvn-004673
Vachetta, 12 mm non-adjustable strap https://us.louisvuitton.com/eng-us/products/shoulder-strap-vvn-vvn-004671