Etek 3 is smoother mainly because it does not use a spring to return the ram, it also has a low pressure regulator so you can fine tune it to be even better shooting. The FX uses a spring to return the ram which results in more vibration. The FX is more efficient, although this may or may not be because of the spring. Logically a spring should not increase efficiency and I believe the FX is just a more efficient marker. Kind of like a Timmy verse an Ego, both are two way's but the Timmy is drastically more efficient, many other factors affect efficiency.
To me, I really notice the vibration. But I'm the kind of guy who can tell the difference between a Phantom with 10 paintballs in it and a Phantom that is empty, and it's kind of annoying
Yea,but another thing between the FX and the Etek is that the FX has an OLED Board,Reversible Double Trigger,Ultra Lock Clamping Feed Neck and a RAPS Lever On/Off ASA