You should notice a difference in levels 6-8 after you've put your initial points into various schools to learn them or by going through different play throughs.
Are you saying you don't notice a 20% in damage over the default?
Now what may be happening is that because you're doing it point by point you end up adapting, visually, to those changes so it doesn't seem like anything but the second you have someone who is a non-pyrokinetic who isn't abusing high ground and isn't critting versus someone who is pyrokinetic who is on high ground and who has higher crit multiplier you'll definitely notice a damn difference.
