I'm a watch enthusiast and I can tell you that a milanese mesh is unisex and sporty and dressy at the same time.
There are many men's and women's watches on a milanese mesh, but it's mostly for men. And of all the bracelet types, the milanese is so tightly knit that your arm hair won't come through and won't be pulled out
Also there are many really dressy watches with this bracelet (like from IWC), but also sporty or dive watches (from Omega and Breitling).
So you guys don't have to worry about the Apple Watch becoming too formal on a milanese mesh, because first of all an almost square smartwatch will never look too dressy. Second of all the milanese looks really good on a t-shirt and jeans when you have a black dial, because it makes the look more sporty. The Apple Watch is all black on the front no matter which version you buy, so it can be down dressed without a problem.
My only advise, don't get the completely black Apple watch, because that will look very off with this bracelet. Scratches will be seen more quickly too on a black watch. A black milanese will lose its color even more quickly, so better stay away from those.
When you are stuck in deciding between the 38mm and 42mm and comparing cut-outs, remember that the height has a lot of impact on size perception with watches. A 42mm Apple Watch will be significantly larger in real life because of the total volume increase. So put a real watch underneath your cut-outs to get a better sense of depth.
One thing I've learnt in the watch world is to never buy a watch you haven't had on your wrist! In real life on your wrist, with your wrist size, with your skin tone, a watch that looks great on pictures can look bad in person or the other way around. Ordering of the internet will leave many people disappointed I'm afraid. Trust me on this
Finally, in my opinion $149 for a milanese mesh is a steal (the bracelet alone from IWC costs $1500)! I'm really curious to experience the quality.