I have new BMW ones installed, but the wing and rear wiper make the hatch excessively heavy. It stays up fine when it is warm, but cold it can sometimes slowly start to loose it until the weight takes over and it closes itself, as the worn ones did without the wing.
I'm getting a set of these lifts and trying them out. If it takes some effort to close the hatch (you did not mention a wiper and/or spoiler) with a stock hatch, they should be just right with the added weight of the wing on my hatch.
I am a bit concerned about the shorter length. I'm 6'2" tall, and if the hatch is lower when open this might be a pain in the skull...
If they work well, I will post the results...