Thanks for your comments! Actually, I built a v0.3 that I didn't release in which it showed the average speed always (from the start to that point in time), and not the speed perceived in that moment. Do you think it would be better that way? Or maybe showing both speeds?
When the transfer reaches 100%, the "average" speed is actually the calculated speed from start to end (and not the speed that was at the very end), so that one is more accurate when talking about averages, just like the first image you shared with the Azure Striker Gunvolt cia.
By the way, my O3DS yesterday had hiccups from 50KB/s to 200KB/s, in the end the average was shown as 120 KB/s. It took 50 minutes to transfer Kirby: Triple Deluxe (which weights little less than 600MB), so I was really impressed with your image showing Gunvolt transfer in less than four minutes! And it weights more than half Kirby; with my speed, it would have lasted more than 25 min.