I’ll go against the grain here and say I like it. I agree the belt doesn’t have enough structure, but the dress has a waist seam and enough darts to keep its shape - I wonder if it might look better without the belt in fact. The shoulders are nicely shaped too.
In terms of the cord and how stiff it is, you’ll only know by ordering it. Needlecord can be very soft - just depends on how much they’ve invested in good fabrics. I find that is a complete lottery with Boden and totally unrelated to price. I bought an amazing, full skirted, smocked linen maxi dress this summer that is amazing quality with deep, double-turned hems. But I also sent some t-shirts back that we’re like rags. All were fairly pricey and only the dress was worth the £££