My experience with Dacron/Mylar laminate was not good...they are too dissimilar in their stretch characteristics and the adhesive
could not hold them together...massive delamination
. I had a brand new jib
come apart after 3 seasons.
My experience with Pentex/Mylar is very positive...no delam after 10 plus seasons and while it shows the expected wear the clothe itself is in very good shape.
Note, this was a racing
application on a beach cat, where the sails
were taken off the boat each night, and I would not use a laminate for any roller furler
With that said, I do not think I would use a laminate in a cruising application...my 1966 Ted Hood
Auxiliary Racing Sloop
is still sailing on most of her original sails, Hood
Sails Dacron, which are still in very good shape. I am not sure I would use anything but Dacron for a cruising application...for durability and maintenance
it is hard to beat.
There are also some newer Dacron application which are pretty slick...in particular a square weave Dacron which I used for the roller filler jib
As for cost...I don't recall
the difference, but not as much as I expected to upgrade to the Pentex/Mylar. I suggest talking with a number of lofts about what you are planning to do...boat, sailing plans/conditions...get swatches of the various options and references
Have fun with the search.