I regularly travel between Tirunelveli and Bangalore by this train. Invariably this train is delayed by > 1 hr each way every time. Especially 17236 - it reaches Bangalore only by 9:15 - 9:30 AM. Thats way too long. They should seriously consider speeding up this train.
Also, I think it would be useful if they could extend the Mayiladuthurai exp to Cuddalore via Chidambaram. Good connectivity to the entire stretch there.