Hey Darrel - I'm sure you don't want to make a career out of this mini-project, but can you explain that result? It's not obvious (to me at least) why it takes so long and the green line never reaches ADval. Playing with this in a spreadsheet, it can take between 100 & 150 samples to get there, but you have WAY more than that, and it's not even close! Do you think this the accumulated result of dropping LSBs, and effectively always rounding down?

Also, to address the ramp time, when I've done something similar in practice, the first time through the loop I make RunAverage = ADval to effectively eliminate the ramp, and at least start in the right ballpark. (I'm sure you typically do as well). Wouldn't it be more fair to add that curve instead (or as well)?