Yes there is a significant difference between conventional- and wing paddles.
Comparing a wing paddle, as used in competitions, with a conventional paddle:
a Wing gives certainly more efficiency in your paddlestroke or you can also say: you can go faster
but a compatition wing has also a downside: not al (support)strokes can be performed safely. Because of the curled, leading edge in a wing the blade can rotate uncontroled at some of the sculling-strokes, but even in a sweepstroke this can happen. When the grip of the blade on the water falls away this could result in a capsize if you donīt recover quick enough.
It would be helpfull if both handgrips are oval.
You can improve by learning, but you should take may be two years for getting completely used to this.
But I think that, under difficult circumstances, you never feel as secure as with a conventional paddle.
Then there is a compromise wing-paddle (f.i. the Lendal Kinetic Wing) Which I use myself now. The blades of this paddle donīt have the curled leading edges and the effect of the wing is created by the model of the blade; a look alike of an airplain-wing.
The rotating-danger with this paddle is much less and after 2 years I feel quite secure now: Being able to perform most strokes. However sculling is still difficult. And when paddling in a bouncy sea, sometimes I donīt feel completely comfortable.
As this paddle is a compromise, the propulsion is not as good as a competitionwing. And also you have to addept another style of paddling to get the most out of it. The problem is that you can easily fall back on your way of paddling with a conventional paddle, thus giving away the profit in efficiency. The competition wing is less demanding there as it forces you itself to the wing-style of paddling, meaning the blades goes aside when pulling. (dont have to think about that)
I feel that now, after almost 3 years, I found and addapted "the tric"
So I am not too surprised that there are not so many wings found on the sea