I been trough the COD twice, two different versions, latest was 4.5. It made a big difference when I started to lab over the volume II labs again even when the labs had good solution guide. I take my time and dont rush through the labs, so one lab can take up to two days. I do the labs and then verify with SG for every time I do a task. Just to get the understanding, I can work with speed later. I did take the first 6 volume III labs, but I use 5 hours on them so I know I have to work with speed. Its not a concern yet.
I would follow a strategy that Brian Dennis mentioned: Take lab 1,7,8,9,10,11 and do them 4-5 times. Do 1 lab then go to 7 and after finnish lab 11 go to lab 1. Just so you dont use the short memory to do the configs. Then pick up other 2-3 labs and do them 2-3 times. I was in IE London bootcamp in april (This time not paying out of my own pocket) and Brian mention this method again, so I sure will follow it. The other thing he mention was that of all the candidates that did the mock labs and passed the CCIE Lab( he have evaluated hundreds) they aced on IPv6. They did not ace on QoS. QoS is harder to verify, IPv6 is not. So next goal is to spend a week just on IPv6 and be really good on that. While I am doing this I will spend time in the morning and evening go through Cisco Doc. I have printed out the 3560 configuration guide and will start with that.