In the Ubiquity RPG system (as used in Hollow Earth Expedition or Space 1889), an alternative initiative system ("continuous combat", where actions take place continuously, without use of combat turns) is proposed in addition to the default system (a turn based system relatively similar to Dungeons and Dragons). Continuous combat is left a bit vague in the core rulebook, but elaborated on in the addendum to the Hollow Earth Expedition GM screen.
What are the advantages (as a GM) of using continuous combat?
Is it very complicated to use?
When would it shine compared to the standard initiative system?
When is it worse?