Just saw this (old) thread and wanted to add my experience with the Centaur vinyl tape fencing.
We used Centaur to fence in about 20 acres of pasture. We bought all of our fencing, posts, gates and supplies from the Hen Yard.
We generally followed the installation instructions noted in the Centaur book. We 'radiused' all of the corners which was rather time consuming, but worth it. It makes for easier mowing and pretty much prevents a horse from getting pinned during an altercation. We put the vinyl rail on the inside of all of the posts. We decided on using three rails.
One thing that I did during our recent expansion was to use exterior screws rather than galvanized nails. I wish I had done this from the start. Screws make any needed repairs or changes much easier. I purchased the screws (Grabber brand, very good quality) at the 84 Lumber in Charlotte Hall.
It was one of the pricier options especially intially, but there has been no maintenace costs so far.