I always knew that Onslaught came with a metal and a plastic chest. Well, I found a 3rd version. I got another (like I need more) MIB one off ebay the other day. It was open but had an un-applied sticker sheet and was very cheap. So, I figured I would buy him, take the stickers and resell him. Make a few bucks and get a vintage sticker sheet for free in the process. Well, that didn't happen. I took him out to make sure he was in good shape and then I noticed his chest was different. So, of course I had to add him to my collection.
If you look at the pics above, I took off all 3 chests so you can see the differences. the first (on the left) is metal. the second is plastic, but the same shade of silver as the metal one (this was the one I got off ebay). The last one is the dull grey version that I "thought" was the only plastic version. I don't know what the #1 and #2 on the inside of the chest mean.
There is also the japanese version who came with an actual "launcher". But I don't own this one, so the pic is borrowed from the web.
Since I'm doing plastic VS metal, here's metal (purple) Swindle vs plastic (grey)
Metal Brawl VS Plastic. Hard to tell a difference in a pic (especially with un-chipped metal), but weight wise.........you can tell. The green is an ever so slight different shade.
And just for fun, here s a little extra something else I noticed.
G2 Onslaught and Battle Gaia have the SAME EXACT face, feet, hand and ramp plates. Same shade of black, same writing and even the same markings inside (which, I forgot to take a pic of. But trust me, they are the SAME). The white used on Blast Off's weapons is slightly off though. the bone white on the left is G2 and the milky white on the right is Battle Gaia
Swindle however is the only one to have the same weapon for all 3 versions of the toy.
And you can see how close the G2 versions were to Battle Gaia. Different enough, but obviously Hasbro copied Takara a little.