There are many things to consider. Wavelength for example, as different materials have variable absorption. 380mW isn't much power though, and unlikely to cut any metal even when focused.
CO2 is efficient for cutting wood, a 25W RF excited metal tube or 40W glass tube would be sufficient for 1/16" ply at a fast cut rate.
Cutting 1/2" aluminum is a different problem, you'll require a several kilowatt CO2 laser to cut at any decent rate.
Diode pumped lasers, like Nd:YAG are great for engraving applications and can be used for drilling holes or cutting thin metals.