YEARS ago now, but it was good fun and I still have the tapes and exercise books.   Saudia ran the course.  I was very keen in those days and wrote out all the declination of verbs etc

However, I learned Jeddah dialect and when we were in Iraq they thought I'd learnt my Arabic in Kuwait LOL

I think it's understandable to most Arab speakers, though ... only one way to find out!