The main issue I have seen with SQL Server was a constant deadlock (every two weeks or so) over a table with high writes (peak at 800k per sec), which was annoy

The main issue I have seen with SQL Server was a constant deadlock (every two weeks or so) over a table with high writes (peak at 800k per sec), which was annoying because the fail-back to the replica affected the DNS entries and meant 5-15min of outage. But to be fair it was an example of the wrong tool used badly in the wrong situation deployed in a poor environment.