I have one 1200 psi.... haven't killed anything with it (or tried, I should say) except two chicks that needed to be put out of their misery. Worked very well for that. Quick and easy. And not THAT quiet.
Ahhh. Air rifles. I've had a Sheridan Blue Streak .20 cal since I was 14 and I'm 41 now. The same rifle. I rebuilt the seals once when I was about 35. I've taken countless squirrels, birds, rabbits, snakes and ferral cats with this rifle. It has to be pumped several times for each shot, but it's fairly easy if your health is good.
Also I treat airguns the same as I treat a real weapon. It can be deadly to humans. They are not toys. So be careful of where your shot goes.
If I had to buy an air rifle again I would try the Gamo that has the permanently attached silencer on it.(google it)
I have a single pump chineese one that I picked up at a flea mkt it's plenty strong ( will shoot through a metal trash can) but the trigger pull is so hard that it's not all that accurate , got to pull out the guts of the trigger to see if I can make the pull lighter .
When I lived in town I had a Crossman, took cats, that was the only thing bothering the chickens. Now that I live out of town I use anything that comes to hand from .22 to a 12 gauge. The Crossman I gave to a woman in town who has Bantys and she has made good use of it. The caliber was .17.
I recommend a Benjamin .22 caliber pump. They will kill some predators. Shot placement is critical. One plus is their silent. Personally, I have killed coons, possums, rabbits, birds,skunks & snakes. There great for shooting up close. There similar to a regular .22 up close. I've never done it but if you get a good shot off you could kill a fox's & definitely make a bobcat run off & probably die. One other positive you can shoot beer cans for practice without spending a fortune on bullets. If you get one don't over pump it & get bullets that are aerodynamic meaning not blunt tips for better accuracy & kill ratio.