Brakes on 1500

The metal-to-metal sound can be called a 'squealing' noise.
I use a small mirror and a flashlight to inspect the front brakes. If the pads are less than 1/8" thick I'd think seriously about replacing them soon. The final pad life wears faster compared to newer pads.

The rears are visible from the back using the flashlight.

There are no wear indicators/squeakers like car pads that I have seen.Honda. OEM are probably the best noise wise,but are way over priced IMHO.Discs brakes will squeal with any small amount of dust or contaminates even though they could be new.Different friction compounds can be worse than others.I've put about 2k miles on in the past week and my squeal comes and goes even though there's lots of pad left.
BTW When it's metal on metal it will definitely be more of a grinding noise.You'll definitely hear the grind when you are just about completely stopped.