I've edited this post a number of times attempting to express an opinion without appearing critical of Power which I am unfortunately unable to do as such can only say the following regarding this.
Many years ago when they were still doing the Sprintex supercharged Sierra's I was a customer and to cut along story short received a quality of customer service and workmanship that was not acceptable to me as such I am no longer a customer

I can't really say any more without being specific which achieves nothing and only provokes conflict of opinions from people.
If anyone can speak highly of them, I am so pleased that you did not obtain an experience such as mine which may go to prove things sometimes change.