when you get 30 iMG from each piece, are they destroyed?
or can you repeat each day, etc?

They're destroyed.

The iMG wrangling does destroy the item, but it helps make up for the fact that one of the pieces is more rare than the others are. Sure beats hanging on to the common ones, hoping for a windfall of Red Fs!

It also means you don't have hundreds of SWFs to drop all over.

and the fact that I am a natural pack rat & have been picking up & saving all those that people have been dropping will pay for the 3 SDBs I made to store them in - I have 47 red & over 60 @ of the other 2. unfortunately, this will just reinforce my tendency to save everything.