It might have been. From reading the post and associated links, it sounds like the penalty is only on first write even without VAAI. With VAAI (I'm using EqualLogic so I have VAAI) that penalty is probably not something the average user would notice and in general, is not worth worry about. I'm better off keeping thin disks and saving space.
To do a test, I added a 100gig disk to a vm and marked it as eager zero. It took 5 seconds to create and I barely had time to find which vaai counter in esxtop was increasing. I also cloned a VM which took about a minute but I also saw vaai counters moving during the creation so I guess things are working as they should.