Yes, it will choke out smaller plants, and I'm not sure how it would affect rhodies, which have shallow root systems.

My childhood home had vinca minor around the feet of azaleas and rhododendrons, with loads of narcissus planted there too. In a shrub/bulb setting I'm sure it would be fine, but not in a border with perennials, which seems to be what you're after. Have you considered ajuga or epimedium? I have no personal experience with either but I've read that they're well-behaved.

Ajuga can be quite aggressive, but it's controllable and it will spread quicky to fill in unwanted bare ground. I am particularly fond of Epimedium, though it spreads slowly (too slowly if you really like it!). It has delicate, early spring flowers (just starting here now; I have white and red) and beautiful foliage, that turns red in the fall. Superb plant, but be prepared to wait for a nice stand to develop.

In my experience vinca only works as a groundcover when it has some sun. In my shady areas it is pretty thin. It is trying to move into my garden beds right now but is hard to dislike when it is flowering.

I am not sure what variety I have but it has grown up the wall on the southern point of my house. A few years ago, I was painting the house and thought I would have to destroy the plant or not paint in that area. Changing from brown to dark blue would have been a spectacle if I had left it unpainted.

When I checked it out, I found that it was not attaching itself to the house at all, It was just strongly leaning up to it. I eased it down, painted the house and use a clip to re-secure it in place. I should have photographed it when it was down.

Yes, the entire point of the house has it growing to the roof.

I will post a close up when I can get ll of the ice off it (:
There is one thick stem from the bottom yet a section of the plant is variegated.

Now it has a clematis growing in it and everyone thinks that the Vinca has 4" flowers when it bloom!

Here are the close ups:

Vinca minor is extremely manageable......Vinca major much less so. In my garden in a wooded setting - mostly shade - vinca minor (periwinkle) grows well and flowers beautifully in spring. It coexists easily with rhodies and azaleas and has never smothered other, smaller plants. If it seems to be growing too aggressively, it is easily cut back or pulled up. Like any plant, it may require some periodic maintenance and attention to keep groomed or contained. Vinca major has a much more rampant growth habit.

Just avoid planting either in areas adjacent to natural or wild plantings as it can spread to these areas if not tended to properly. YOU may keep it contained but subsequent owners may not :-))