Storing Documents as Blobs in a Database - Any disadvantages?

Solution 1:

When your DB grows bigger and bigger it will become harder to backup. Restoring a backup of a table with over 100 GB of data is not something that makes you happy.

Another thing that get is that all the table management functions get slower and slower as the dataset grows.
But this can be overcome by making your data table just contain 2 fields: ID and BLOB.

Retrieving data (by primary key) will likely only become a problem long after you hit a wall with backing up the dataset.

Solution 2:

The main disadvantage that I often hear of using blobs is that, above a certain size, the file system is much more efficient at storing and retrieving large files. It sounds like you've already taken this in to account by your list of requirements.

There's a good reference (PDF) here that covers the pros and cons of blobs.