BF3 (beta) C4 key points:
- The support kit unlocks C4 around level 15.
- It takes 2 pieces of C4 to "disable" a heavy tank. This doesn't kill the occupants.
- It takes 3 pieces of C4 to "destroy" a heavy tank. This grants the disable, destroy, and kill occupants points.
- As in BC2, C4 can be thrown by jumping and clicking the left mouse button. Right-mouse button detonates C4.
- C4 doesn't fly "superhuman distance" as it did in BC2. It flies, at most, 2-3 meters. This means it's still possible to C4 a tank without kissing it, but it's much harder than in BC2.
- C4 is "sticky" for the entire duration of its flight. This means that it'll often stick to cover instead of flying over it. You pretty much have to be on clear open ground for C4 to "fly" further than 1 meter.
- C4 will cause damage and destroy certain parts of the environment. However, compared to BC2, there is a very limited amount of destructible things on Metro and Caspian.
- C4 pieces resupply very quickly. It takes (my best guess) about 2-3 seconds to resupply a piece of C4. Considering you're already support - it's very difficult to run out of C4.
- C4 pieces do not show up with mini-markers on the ground, as they did in BC2. This means that spotting a tank and waiting for its minimap marker to align with the C4 "mine" marker on the minimap doesn't work. Visual acquisition required.
- I do not know if it's possible to "spot" enemy C4, in order to warn friendly players of it. I haven't seen many players using it.
- Caspian Border has many, many tanks for you to enjoy your C4 :)
I definitely enjoy the balance changes to C4 in BF3.