Just tried out the Crysis 3 beta, had a few problems, the main ones being:

The sensitivity slider isn't precise enough as it only goes up in steps of 5 so I can't get a comfortable sensitivity, it's either too high or too low.

Sensitivity when aiming down sights actually seems to increase compared to hipfiring making it impossible for me to aim accurately as I'm used to BF3 where the sensitivity is halved when ADS. Is this just part of the game or is it just an issue I'm having, or a widespread issue?

On top of this I'm using an i5 2500k @4.3GHz, GTX 570 OC, 8GB RAM, and on the lowest settings I get between 50-60fps, meaning I physically can't have a smooth gameplay experience because it's impossible to achieve 60fps consistently. I expected to run it at 60fps constant on med-high settings but obviously that's not an option. Changing from medium to low barely does anything either, it's a couple of frames or so.

I agree, the jump from 5 to 10 is quite troubling.