I would appreciate some guidelines regarding when I should turn on / off the use of the Kaseya Reporting service.
When should I use Kaseya Reporting Service? When should I use MS SQL Server Reporting Service (SSRS)?
Here are some guidelines:
If SQL is installed on separate box, use SSRS to remove the reporting load from the VSA server.
If SSRS is already configured for their environment, then use SSRS.
If you are using a double-byte language (i.e. Chinese, Japanese, etc.), then you must use SSRS.
If you are concerned about the size of generated PDF files, you should use SSRS.
If you are using Kaseya Reporting Services and you experience performance issues related to reporting, then you should use SSRS.
If any of the reports may generate a large number of pages, then you should use SSRS.
If Kaseya Reporting Services is enabled, then the VSA will ALWAYS use Kaseya Reporting Services. It will never use SSRS.
The information above leads to the conclusion that all but the smallest customers should use SSRS.
The original purpose behind the Kaseya Reporting Service was to allow for easier installation, without having to install and configure SSRS.