My experience with powdercoat is as follows:

It holds up pretty well and is easy to apply.  It is a bit more durable than paint -but it can chip and scratch.
It is not good at filling or flowing into seams.  I have had car wheels powdercoated, and I have bought factory trailer wheels that are powdercoated - and the rust starts to show at the seam where the inner part joins the outer rim.  When the powder is applied it covers the seam - but when heated and melted it does not flow into the seam.  For this applicaiton I always take some matching paint and flow it into the seam after the powdercoating is done.  (This should not be a problem on a Savage Tank - except for the mounting tabs.)
Powdercoating can fade if left in the sun.  I have a mailbox that was powdercoated and the silver box is fine - the red flag is now pink after being in the sun for 5 years.....but there is not any rust.
Powdercoating is not an extremely shiny paint - it is more of a satin finish.  It can be clearcoated with paint or clear powder and the shine becomes better.
It is resistant to fuel lifting the paint - but I am not sure about staining as I have never had anything powdercoated that is near fuel.  I just ran by a local place that does a lot of powdercoating for cars.  They said they have coated intake manifolds and they hold up well, and they have done a few of the small fuel tanks for race cars - but have not had any follow up.  They think it wold hold up OK....but don't know about staining if the fuel was spilled on it frequently.

While I was at the powdercoaters I saw some of their fencing that shows the seam problem.  The powdercoat is electrostatic and just like chrome plating - it is not pulled into seams very well.