Gamma Ray Bursts -- Fireballs or Cannonballs?

Has anyone else been paying any attention to the fireball versus
cannonball dispute?
It seems to me the cannonball guys have some fairly strong points, but
no one else seems to agree.  Why is this? Is there a fatal flaw in
their argument? Why are fireballs so popular?
Inquiring minds want to know...
TIA
Jim Graber

[Mod. note: strangely mangled subject line fixed up -- mjh]