It's just a vertical roaster. Obviously an actual vertical roaster is better than a beer can.
If you want to spatchcock your chicken, you can do that, but you will lose the juices and it doesn't look as good.
If you want to rotisserie your chicken, you can do that, but you need £100 for the rotisserie.
But otherwise a vertical roaster is a very good way to cook a chicken. The beer can, not so much.
I can plonk a chicken on here:
stick it on the grill and it's done.
And I've got a couple of ounces of chicken juices in the roaster to use as well.
I don't see anything in the article there that persuades me that, short of buying the rotisserie, I can get better results than I achieve on my 'beer can' (which isn't a beer can and which I fill with water, not beer).