Cut out dresses have a reputation for being the thing you wear once to be photographed in and never again, and for a long time I believed that completely. The ones I tried were either so fussy with their straps that I spent the whole evening adjusting them in a toilet mirror, or so skimpy that sitting down became a genuine strategic decision. I've come round on them, but only the versions that are honest about where the gap actually goes and why.
Before you buy, get your hands on the dress and check where the cut out sits against your own body, not the model's, because a waist cut out drawn for someone five foot nine lands somewhere completely different on someone five foot four. Check the edges of the opening are bound or faced rather than just cut and left, run a finger round it, if it feels raw or flimsy it will fray or dig in after one wash. Check how the cut out is held together, whether there's a bit of elastic, a strap, a clasp, and whether that bit feels sturdy enough to survive you reaching up to get something off a shelf. If you own none of these, start with a small side cut out or a modest back opening rather than anything at the waist or ribs, it's far more forgiving of normal movement and normal lunch, and it reads as considered rather than attention seeking, which matters more on a high street budget than people admit.
The difference between a good one and a disappointing one almost always comes down to fabric weight and the construction around the opening. A dress in something with a bit of body and stretch will sit against the skin properly either side of the cut out, where a thin, floaty fabric gapes and shows more than intended the second you move. Look at the stitching right at the point where the cut out starts, that's the stress point, and if it's a single line of stitching rather than reinforced, that's where it will go first, usually on a night out rather than at home where you'd notice calmly. Lining matters too, a dress that's lined properly through the body but not across the cut out itself tends to sit better and crease less. For wearing it normally, it pairs best with the plainest shoes and jacket you own, a flat sandal, a simple denim jacket for the walk there, because the dress is already doing the talking and anything else competing with it just looks busy.
Whatever version you choose, it will never be the dress for sitting on a hard chair for three hours, and no amount of good stitching changes that.