Please explain why he's wrong coinhunter.
Sure, since the difficulty can only raise in three bands 2%, 6% and 10%, and decrease to whatever level is necessary (upto 4x) where is he getting this 20% figure from?
If we are at target hash rate it will maintain that level within 2%. The other thing to consider is the target hash rate is more like "the maximum" wanted, it's different to BTC where 10 minutes is "Desired". "3 minutes" isn't necessarily desired in SolidCoin, it's the maximum.
Well, my reasoning was that the difficulty is calculated from the time it takes to generate 240 blocks, and that time varies +-20% all the time. However, you are correct that limiting increases to 2%, 6% and 10% stabilizes the difficulty, but it stabilizes it to a level below where you would get a block every 3 minutes. But apparently that's what is wanted?
I still claim, that difficulty drops can be quite big just from the variance, if not as big as in my example (33%), but say 20%. It certainly will not "maintain that level within 2%", or I'm completely misreading the source. However, since those kinds of drops are corrected very fast, it might not be a problem in the end.