It's quite invasive and readily invades wild areas. I have seen acres and acres of woodlands in central NY state filled with it. Same here in WV.

My MIL has it in elevated planting beds w/brick borders around her trees and it definitely fills in nicely - I wouldn't consider planting it with other perennials, but it also stays in her planting beds - it doesn't stray.

As with any so-called invasive plant, its invasive properties are determined by location and planting situation. As noted, in some parts of the country, vinca is a listed invasive, escaping cultivation and invading natural woodland areas. In other parts of the country, it is only an aggressively spreading, shade loving groundcover.

Vinca is used widely in my area, as yet with no indication of it being a truly ecologically invasive plant. IME, it is best used to cover an otherwise unplanted area or with larger growing woody plants, like trees and shrubs. For example, it makes an excellent groundcover with rhododendrons and azaleas or under large conifers. It doesn't play all that well with smaller, herbaceous perennials, as it can easily overwhelm and smother them. And I would avoid planting it in any area that would allow it to spread into any natural plantings, like open woodlands.

I would take it back and try to find a better "team-player," preferably a native. Hubby seems interested enough to appreciate being educated on your reasons. Personally, I don't think this stuff looks good anyway unless it has its' own area to dominate. I don't think it's a battle you want to fight in a bed that has other plants.