@claymore
You should make the -li 1 default. It does have a major impact on temperature and I guess power usage with no meaningful decrease on hashrate. In fact Tahiti and Hawaii have no hashrate decrease at all. Ellesmere shows a decrease of 4 or 5 hashes.
Did you experience significantly lower temperature and/or lower power consumption? I never used low intensity mode and can't test my rigs now with "-li 1" parameter.