Highstick, I talked to one of the suppliers of Gordon Glass about this. What I got out of the conversation was this, the scrim glass is a little bit better grade because of the unidirectional support. He said when handling it in sheets it was definately less likely to brake. BUT, once it was cut down to 1 1/2" or 2" it really didn't make that much of a difference.
That being said I always use the glass with scrim because in my experience I've found it's usually looks a little better and has fewer blemishes or streaks in it.