Alternate Tread Stairs

I am contemplating use of Alternate Tread Stairs which would be fundamental to a small project. But I have never (or it has been 30 years) used such stairs. The investment is substantial and I won't do the project unless I like how the stairs walk.

Would like to know if anyone has used them and even better if there is such a set I can "try out" some place within, say, 200 miles of Seattle.