Ohhhh, ohhhh, ohhh....my turn. Actually the difference between 1.1 and 2.0 is that in 2.0 the Binary format switch during Serialization actually works.
I believe the switch was present in 1.1, but even after creating a file with binary turned on, you could pretty much read the contents since so little conversion to binary had taken place. You're right, Horshack! ;)
Yeah, I forgot, there was a property in 1.1, but it did very little. In 2.0 it compresses the file by a factor of at least 6.