Dear Silverhead,
Line 6 advertises that a player can access 28 pre-set guitar models using just the controls on the guitar, that is, not having to use some other equipment or special software. For players not as familiar with computer modeling as you and many forum participants are, this is quite attractive.
The methodology for calculating that number is clear. Using that methodology, the current number is 23. Line 6 has apparently modified their manuals accordingly. It should modify its advertising to be consistent as well, including so that potential buyers are not uncertain if they are getting correct information. If I was in the company, I would not see this as criticism, but rather as constructive feedback from the customer base.