I have the same problem.
With Shadow Play I record with 170-180 fps and when I recording with Action I have 90-100 fps when I play Warface.
On Wildlands with Shadow Play I have 60-65 fps with Action 20-30 fps.
On Black OPS III with Shadow Play I have 50-60 fps with Action 25-30 fps.
On Overwatch with Shadow Play I have 120-130 fps with Action 60-70 fps.
Even with OBS I lose some fps but not so much like Action. Is not normal if we think that Shadow Play and OBS are free and Action is commercial.
Windows 10, I7 4700HQ, 16Gb DDR3, GTX 770M with 3 GB DDR3, SSD 840 EVO 250GB (SATA-III)