I had the same problem when I switched. I have never been able to get as much production out of my freestyle.
One thing that helped some was to go back to the regular breast shields rather than the soft fit. If you have the personal fit kind (the ones that come in two pieces), then you can use them w/ your freestyle. If not, I'd call medela and explain your problem and they will probably send you some.
I kept my freestyle for "on the go" use, like outdoor concerts and such.