Gold instead of Diamonds.
Diamonds don't register that well with the viewer and they feel like they watched a heist film where the bank robbers stole nothing.
This is probably a major reason production on a 2nd film in the series hasn't moved forward despite the first being a major success.
No one Gives it to you...you have to take it
I'm inclined to agree with U BUT gold is VERY heavy but diamonds aren't, remember that.
Spoiler alert for them spoil sports out there! Y'all like spoiled milk, stop crying over it!
(1) the main point of the heist was retribution, redress, and justice -- not robbery;
(2) the ring and diamonds were previously stolen property from wwii injustices;
(3) the ring represented and served as proof of both the above;
(4) gold is dense and tends not to be as valuable as diamonds.
So you wanted the guy to lug gold around , ruin his whole plan , because it would "look better"?