I like them a lot. I wish I would have bought more when they were cheap, along with more pillar dollars. They are getting to be pretty popular, so expect to pay good prices nowadays. I am seeing all good south and central american bringing much stronger prices now than in the past.
I always liked the pillar and waves most of all but of the bust designs that one of Ferdinand VII was always my favorite. I was also always quite fond of the much older pillar and waves design, minted in the actual home of Hernan Cortez himself.