................Fisher Boat covers?

The barn storage deal fell through and I will be storing the boat in an
outside yard (at least it is free). I already have the boat covered with a
full mooring cover (in fair condition but with some small holes in it) and
will probably add a 6 mil plastic cover over it supported by a simple PVC
frame. The yard is open to some pretty strong winds in the winter and the
yard owner advised me to double tarp it.

Next year I may be looking to upgrade the winter cover to a Fisher cover:

http://www.fishercanvas.com/CvrGuide.htm

I was already quoted $700 by them for a custom fit cover for my exact boat.
These covers are expensive but are supposed to be top shelf and have close
to a 10 year life expectancy. If that holds up, $70/season is not bad.

Do you have any experience with them?