Roadmaster's answers seem complete to me. Good info and advice.
I have one sword in my 40b, purchased ~6 weeks ago at 6". My substrate is BDBS, with root tabs and other ferts. No dirt in this one.
It is now spreading leaves across the top surface, and I'm hoping to get it moved over to a new 55g setup for more height. It'll likely push at the front and back then, but at least it'll have more height. Awesome plant, looks great. It's growing well outta sand, for now. Lots of other plants, all doing well.
I have some mico/mini swords (no idea what these actually are), with leaves the same sword shape, but scaled down to a max of 5" height. Had those for two years now. In hindsight, I wish I had more of those for the 40b, instead of the monster.