Me neither. Never had the use for one.
Never heard of Elcaset. (Whoosh)
Basically it was a larger version of the cassette but the tape was much wider and ran at twice the speed, which gave it a performance equivalent a reel to reel recorder at the same speed, but as it had Dolby (Most consumer reel to reels didn't ) it was actually better. (Pro studios used Dolby A with their reel to reel recorders)