I don't have anywatch tower setup and maybe I should have one. Maybe I do that in a near future.
When a Lightning node is online 24/7 why would you need a watchtower for it? From my understanding of LN only reason I would consider an independent watchtower if you want a protection for your channels should your Lightning node go offline for some unexpected reasons. If offline periods are rather short (say less than ~30min) and scarce, I wouldn't bother to setup an independent watchtower. (I might be wrong, though.)
Well you can never know if / when you have internet and / or power outages and how long those will last. If you have full confidence in your infrastructure and your locktimes are set long enough, there shouldn't be much to worry about.
You should also factor in how good your backup solution is and how quickly you can spin up a backup of your node in case of a hardware failure. Like: how long does it take you to get a new hard drive (or even whole new server in the worst case), download the whole blockchain and install all the necessary software, and is your channel locktime longer than that?