ah you can argue the whole day about ghosts, emp counters infestors good, idra is right

Zerg detector = 100 gas and easy to kill,
infestor = 150 gas and useless without energy
ghosts are relatively cheap gaswhise + they can kill Z detector and have cloak and dps
Zerg depends extremly on gas in middle/lategame, good hitting emps are brutal

its like flash is complaining about darkswarm because vessels are so useless =), start using ghosts and stop complaining