This has been an age long debate on whether to use GUIDs or INTs. Thought I would pen down some points based on some tests that I ran on my test machine.
SQL Backup softwares can cause Out Of Memory conditions if the BufferCount and MaxTransferSize is not taken into account on 32-bit systems:
In the recent past, I worked on a few issues where the use of monotonically increasing clustered index keys were turning into hotspots in the database leading to latch blocking and causing performance degradation as an end result. I illustrate this with the help of an example in the blog post below.