This was a great article. I was researching why DevExpress XPO was doing this on the back end as well. Keep in mind, this is derived from the system.data.sqlclient class and most of the ORMs inherit that class to build on top for SQL server.
We realized a 8X difference, on average, from changing the datatype. I will say we have high performance SANs and multi-proc servers to handle the storage and CPU load, but this kept me from having to go clustered and deal with updating multiple servers and increased performance like night and day.
This article was a God send. I really appreciate the effort!