WHunter, I still can not figure out what you are intending to say...

The loss of system efficiency due to changing to the less efficient R134a molecule is widely accepted as about 15 to 20 percent. This is why I thought your 2 percent was a typo...that you meant 20 percent.

"Roughly 2% system fluid capacity loss."
Since you state you can pull 98 percent of the oil out of a system with your equipment.... is this 2 percent related to that statement? And perhaps stated backwards ?
98+2=100 ?

Since AC refrigerant is measured by weight... since it is only liquid under certain conditions in which seeing how much fluid is present is not usually possible I did not think you were referring to the refrigerant.

Your use of the term ' capacity' as compared to amount in the system made me think your original statement ( which it looks like you have edited out ) referred to cooling capacity of a system.