On recommendations here, I switched to it 2 or 3 months ago from Gmail, after Google announced they were going to start charging for Gmail on custom domains. I'd no previous experience at all with running my own mailservers and had always been put off by how complicated it seemed.
Even with a non supported configuration setup [running the mailserver for my domain on a separate VPS from the domain itself] MIAB setup was pretty easy. I had it installed and was up and running in no time. I then spent a couple of days setting up the various DMARC MTA-STS policies etc. [most of that time involved looking up what they were and why I needed them!] and [after testing with an unimportant account] migrating the rest of mine and my family's and friends' emails across from Gmail. I was able to import half a dozen accounts from Gmail with about 8GB of emails between them, using ImapSync [1]
So far [fingers crossed] it's been almost painless. Giving the lie to the commonly held belief that running your own mailservers needs constant hands-on maintenance. My MIAB setup runs quite happily on a $5/month Linode [I checked the IP was not on any blacklists, before I started] and the whole thing has been pretty much 'fire and forget'. MIAB sends me weekly reports on what's been happening. Software updates are a one-liner in the terminal and I've had no trouble whatsoever with Google, Microsoft etc. as regards the mail not getting through.
If you've always hankered after running your own mailserver but [as I did] thought it was too difficult and required too much 'hands on' tinkering, I heartily recommend you give MIAB a go.
DISCLAIMER: I run a couple of dozen email addresses on 3 or 4 domains on my MIAB. Probably sending and receiving a few hundred emails a week between them. YMMV if you're a heavier user than this.