First let start on DeAgostini Japan, JSDF Collection only for Japan but still can find some on the website if you want to.
JSDF Type87 AA-Gun

Open inside actually nothing, is all made by plastic the quality is harder than Easy Model for sure.

But still got some weight, it actually have mix metal inside, but where?? Show you another one.
JSDF Type99 Artillery

Inside still empty got nothing.

Now here where the metal is, is screw mix under the tank.
You can see that whole rectangular is metal actually, then other is plastic.
That why it weight some.

The good on this collection is all detailing cuz it made by plastic,
the tank track are rubber soft track.
The bad is painting all are same nothing special, no weathering, no diecast.

Then let see the Easy Model
M2A2 Bradley
Sure detailing, Good~

Can see the black metal plate screw inside for sure. All other is plastic.

Soft rubber track for this model, acceptable.

Challenger I

Still screw a metal plate insdie for weight.

The bad is the tank track is juz plastic not soft rubber track.

The good on Easy Model are very cheap and detailing on most armor and tank.
The bad is cuz is too cheap sometime will get bad QC and not diecast.