in my opinion a conplete cloak would be too big of an advantage, a semi-cloak or some way of detecting a cloaked ship would balence things out
example using phasers: :stun: vs :stun:, one phaser fires and barely misses the other :stun:, whick cloaks, and switches to :vaporize: without the other :stun: knowing, it deacloacks, and :vaporize: fires, instant win for :vaporize: