- Deploy times are certainly slower, up to 50x slower than non-containerized. However, we're talking 30s deploys versus 20 minute deploy times, all-inclusive. The sidenote here is that you can drastically reduce containerized deploy by putting in some effort: make sure the (docker) containers inherit from other containers (preferably self-built) with executable version that you need. For instance, you might inherit version X of program A and version Y of program B before building only a container with version Z of program C, as A and B barely change (and if they do, it's just a version bump in the final container). Even better, just build a code container during deploy (so a container with essentially only code and dependencies), and keep all the executable as separate images/containers that are built during development time;
- Containers do allow high-speed fixes, in the form of extremely simplified rollbacks. It is built into the entire fabric of containers to allow this, as you just change a version number in a config (usually) and can then rollback to a non-broken situation. Worst case, the deploy of fixed code in my case does take only 20 minutes (after the time it takes to fix/mitigate the issue, which is usually much longer);
- Local environment is _so much easier_ with containers. It takes 10 minutes to setup a new machine with a working local environment with containers, versus the literal hours it can take on bare metal, disregarding even supporting multiple OS'es. On top of that, any time production wants a version bump, you can start that game all over again without containers. Most of my devs don't ever worry about the versions of PHP or Node they are running in their containerized envs, whereas the non-container system takes a day to install for a new dev.
Containers can be heavy and cumbersome, but in many cases, a good responsibility split can make them fast and easily usable. In the specific case of docker, I find treating the containers like just the executable they are (which is a fairly default way of dealing with it) works wonders for the easy-and-quick approach.