I had both the FX3 & FX4, but sold the latter as I was offered a generous price and didn't need two. I am happy with the FX3, though it is only used once or twice per year in order to make sure it still works. The FX3 is easily strippable and serviceable.
Don't rush the operation of the handpump, use the weight of your body rather than muscles, and they are OK. If shooting a lot with a rifle using a lot of air, such as .25 upwards, I would question whether they are practical. If handpumping such a PCP three or four times per day I think that 95% of people will find it too straining. Filling once or twice per week is fine. If you're limited to two or three hours shooting time per week, and need to refill a few times, I'd question whether people would really want to spend a good part of that pumping your rifle.
I would feel naked without a handpump as backup to a tank.