There is a major problem with people and the use of unguided beams. If for example Frieza throws a death ball and Goku tries to counter it with a kamahamaha Goku gets stuck into a powerstruggle, but Frieza is free to fly away and throw another death ball at Goku. Goku not having anyway to defend the second death ball is stuck in a ps waiting to die. The samething happens with special beam cannons, spirt bombs, shield attacks, and big bangs. Either both people should be stuck in the PS or neither should be in the ps. Its unfair to only stick one in it.