Should I use separate log files or log everything to the journal?

On my personal server I currently have multiple services (web server, mail server, etc) and some of them have their own log files while others log everything to stdout and that gets picked up by the systemd journal.

That means I have separate log files for some services, while others are in the journal; I feel that's inconsistent and I'd like to log everything in the journal so I have only one place to check for logs.

Is that a good idea ? I'm worried some high traffic services (web server) may overload the journal; I'm not sure how resource-hungry logging to the journal is compared to a basic text file.