I have used the Hyacinth in my pond for the entire time I have had the pond. By placing one or two plants in during the spring time I have many (about 150) by fall. They all Die off and I just pull them out of the pond. When they are in there they are very very good for the pond. They take up neutirents that might cause FA to form. They provide shelter to smaller fish and shade for all. They are typically free floating and as such do not root down and cause problems.
In effect I would liken them to Talapia. They add benefits to the pond and both help control FA and other plant matter. They both die off in colder climates. They add bio diversity and fun to the pond.
I say as long as your climate has some ice forming or freezing conditions, you are good to go as long as you don't mind removing the dead plants each year (not hard to do at all - takes about 15 minutes in my pond) They are a great addition to the pond and to the eco system.
Pic of them around the edge of the pond:
Pic of the flowers:
