Yes, it works very well. Earlier this year AWS automated the process of setting up a cluster backed by a spot fleet[0]. It's a very cost effective way to run lots of containers.

We actually use a combination of on-demand and spot container instances in production to keep costs down; we have some logic to provision more on-demand instances in case of multiple spot outages.

[0] https://aws.amazon.com/blogs/compute/powering-your-amazon-ec...