it just depends on how you use him but heres the laydown on him from me
Melee: When he doesn't transform he's just plain crap,but when you transform your opponents will go w00t?!
Kiblasts: Self-explanatory
Generic beam: ' '
Kamehameha: Why'd he have to be one of them with the KHH??Anyway it is pretty strong even when you are not transformed,but PSing with other mediocre beams like Galit Guns when on an equal PS,you are most likely to lose....
Destructo DIsc aka Kienzan: All I can say is that anyone who gets killed by this is branded pwned because it's a handicapped Frieza Disc
Solar Flare aka Taioken: Big eater of ki but saves you if used correctly,blinds opponents for some time.
Scatter Beam: All I can say is....KILL THE WHOLE SERVER!!!(sorry for the caps,but it is true)
It really depends on how you use him,in fact the way you use any character affects your overall performance,so lets say you are used to using weak attacks and focus more on melee,you use Trunks,Gohan or Krillin
And the list goes on....