We've been testing FILESTREAM with ERSI Attachments. You might be OK using it as long as you don't need to replicate or move the data. Essentially, enable attachments on a feature class. Go to you SQL database and enable and configure FILESTREAM. In SQL, go to the ##_ATTACH table that was created from enabling attachments. Generate the SQL code to create the table. Delete the ##_ATTACH table. Modify the SQL code to add a rowguidcol at the beginning and set the DATA field to fe the FILESTREAM field. My query statement is below. For some reason I had to add an extra [varbinary] at the end for the statement. I just deleted the field after the table was created. At this point I was able to add attachments in desktop and you could go to the folder on the server where you specified as the FILESTREAM folder and see some files were created. I haven't figured out how to move it yet because XML export fails on a table with FILESTREAM enabled.
CREATE TABLE [GIS].[FACILITYSITEPOINT__ATTACH](
[RowNumber][uniqueidentifier] rowguidcol not null unique, (ADDED this field)
[ATTACHMENTID] [int] NOT NULL,
[REL_OBJECTID] [int] NOT NULL,
[CONTENT_TYPE] [nvarchar](150) NOT NULL,
[ATT_NAME] [nvarchar](250) NOT NULL,
[DATA_SIZE] [int] NOT NULL,
[DATA] [varbinary](max) FileStream NULL, (Set this field as FIELSTREAM)
[FileStream] [varbinary](max) NULL (Added and deleted this field)
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]