This is applicable to you based on your experience Les. The other side of the coin I develop 400 tmy with exactly the same times for 8x10 and 120, even though I beleive the emulsions are different, the results seem to be the same.

You know the factors influencing developement are too numerous to make blanket statements like this and IMO they just as likely to produce overdeveloped negatives as not.

I guess like most anecdotal experience, it seems to work for some and not for others.