chiam is a gracious person who keeps the bigger objective in mind. chee on the other hand only has vengeance against the familee as his main agenda. the "bigger" picture doesn't seem to be in his mind.
When Chiam failed to convince the CEC to censure Chee, he threatened to resign as Secretary General of SDP. He probably over-rated himself and didn't even know that his CEC had been damned piss off with him for the way he treated them. In the end, Chiam resigned and stayed on as an ordinary member when the CEC rejected his resolution.
But Chiam pettiness was in full display after he won Potong Pasir under SPP. Instead of performing his role as an opposition MP checking on the govt, he criticised his formal colleagues whenever he could find the opportunities and became a willing political tool of the PAP to be used against SDP. This is personal vendetta at its best fully demonstrated by Chiam, for those who still don't quite understand the meaning.
Chee, on the other hand, has concentrated on the big picture by attempting to bring reform to the system created by LKY, which is engineered to keep PAP in perpetual power. In doing so, Chee became one of several victims of LKY's sledge hammer, relentlessly pounded and crushed.
LKY has always been personal in his attacks against his political opponents, especially those who are highly capable, using outright lies, half-truths and a sycophantic media to manipulate public perceptions and opinions against those he deems to be a threat.
What Chee has been doing is to lay down the facts and truths for Singaporeans to know and make the final judgements themselves.