Writes and changes to the database itself are locked to a single process at a time, per your link.
If the load is very read heavy the write locks aren't an issue, but if you're tracking page views, comments or any other write-heavy feature, it'll be harder to get good performance.
If the load is very read heavy the write locks aren't an issue, but if you're tracking page views, comments or any other write-heavy feature, it'll be harder to get good performance.