I did a little in college. Not an expert by a long shot though.
Iaido is a fascinating art, I really dug the philosophy part of it where it teaches you to really love life and pay attention to the little things but at the same time be willing to risk it all in one motion.
It's also cool 'cause you get to use real swords. Though at first you will use a practice aluminum sword and wooden sparring sword before you graduate to a real sword.
Iaido is not fencing, there is some sparring involved, but mostly it is a solo martial practice, including the various motions of drawing the sword and cutting straw mats. Keep in mind, Iaido traditionally was a supplementary skill taught to swordsmen. In other words, you get your sword-fighting skills elsewhere, Iaido teaches ambush drills and one-cut kills. It's quite practical in that sense.
What I really didn't like about it was so much time was spent kneeling on hard floors, my feet aren't meant for that kind of torture. I will never be kneeling on a hard floor, caught "dozing off" and attacked by a sword-wielding assassin. In that sense, it's not practical.