The downside is that you need to regularly update your server software and OS. Otherwise you will eventually get hacked via an old vulnerability.
There is a learning curve involved in running linux, you can't get away from that, but that curve would have been substantially steeper without it.
To keep your system up to date with it is trivial..
(not connected, just a fanboy)
Yeah, you better do release upgrades manually--but that is once every few years.
Latest Stable release: 1.03 / June 15, 1998