i love the chain whip, 3 section staff as they are flexible and can wrap around blocks but they are most difficult to use. the straight sword has some of the most beautiful forms displayed.
I remember the guy "Su Chen-Ping" in born invincible when he pickup the sword to fight with Carter Wong. The small performance he shows damn is nice and from a great quality. :)
About flexible weapons they are the most difficult to use indeed. Where I learn shaolin Kung fu the students have to learn first sword staff spear then after many years you can choose those flex weapons. :)