They are easy here (Sunset zone 15).

I've only cut a stem for indoors once and remember thinking they were better than Dutch iris (very similar appearance) for a bouquet since flowers opened successively. I think the stem lasted a week.

Here is a link that might be useful: Spuria Iris Society

They're easy here as well, although my first one took two years to flower after being divided. I've read they don't take to that as well as other irises. Other than that, they're easy and don't take any special care at all. They like the hot and dry summers here and are just fine through the cold/semi-cold winters.

I got my first few from a friend's neighbor who said we could take them, and then last year, I just happened to come across a local place that was selling them. Never ordered them online, though.

I have about 30 different Spurias in my garden. They do very well in my area. They are slow growers, so do not move them often. Leave them alone and they will do just great. They put quite a show in the Spring.

Here is a link that might be useful: Iris Lover