I've wondered about this same thing myself and posted something about it a while back.
Maybe it was just my imagination, but the 50 gm tins seemed to be somehow "brighter" in flavor. At least initially.
The age of the tins also plays into this of course. And it makes it difficult to come to any conclusion since I didn't have opportunity to do a side by side comparison with the same age dates, 50 gm vs 100 gm.
Now smoking from a 100 gm tin, which had been opened and transferred to a Mason Jar. So it's been exposed to air for some time, and I typically reach for this once/wk, usually on weekend mornings as the first pipe of the day.
Got to admit that I don't really see any difference from the 50 gm tin. Perhaps the amount of 'baccy plays a role in this.
All to say that I don't now really feel there's any difference. At least as far as I can ascertain. It's the same 'baccy. Just a larger amount, which must affect the ageing and development potential. And therefore must play a part in the initial perception.
That's how I look at it, FWIW!