Common attribute and recorder

If I add a common attribute (for example comment) and then I use it in query like

Recorder.Comment

Please use common attributes to split data for areas (service mode), as they were designed for that purpose. It is not recommended to use them as ordinary attributes, even if those attributes are widely used in your application. The exception is containing common data and no business logic, like comments or last modification date attributes.

Why it is not possible to use common attributes? It seems to me I have seen some example using them for comments and similar things. Could you give me technical explanation why I should not use them as an attribute without splitting.

And what do you mean by service mode?

It is possible, but not recommended, as it is designed for other purpose rather than it was in 1C:Enterprise 7.
The service mode is a mode of 1C:Enterprise operation for SaaS solutions: where in a single infobase several abonents can have accounts and operate with their own data area only, never see other companies' data.

But is there any downfalls? Should I expect some bugs, reduction of performance? I am worried because I am already using it and not just for data splitting. It makes configuration structure much clear and easy to handle.

One more question? Does it stored in the same table where document attributes stored? So If I use Recorder.Comment it want affect performance because system either way has to get Presentation for Recorder.

I still recommend you to use ordinary attributes because platform developers will apply less attention to the functionality that is not used in a recommended manner. For example it could not be used in the document journal as a column.

It is stored as an additional column, not as a separate table.