Each of the Infantry AT weapons has its own pros and cons.
Panzershreck Pros: Longest range, biggest warhead, virtually guaranteed to kill any allied tank it hits. Cons: Massive muzzle blast leading to every enemy in the postcode knowing your location.
Bazooka Pros: Decent range, far lower muzzle blast. Cons: Smallest warhead, spaced armour often defeats it.
PIAT Pros: Second biggest warhead, no muzzle blast = very sneaky, tanks & players may not even realise they are under attack. Cons: Shortest range, accuracy poor at maximum range, spaced armour may defeat it.