Yes. Assad and Gaddafi are very different. Gaddafi had all his defense system centralised in particular areas of his country but Assad has all his military and defense system built in the residential areas where thousands of civilians live. Any attack on his defense system will surely end up with a loss of 100s and thousands.

For a moment if we agree (though I wont without any proper evidence, just as a case) that Assad used chemical weapons :

"Assad used chemical weapons and killed people ( civilians ), we will use weapons and still kill people ( civilians )"

What is the difference?