It would depend on your latency...
In my case, its usually 50-150 milliseconds.

Losing 0.10 of a second per step in the sequence, would likely be a lot more damage gained then to just ignore Eclipse procs.
If you were to run with .400 seconds latency, I'm not sure on that.

I'm using my IS Boxer keymap for Eclipse anyway, so in my case the castsequence is a theoretical option for someone who just wants to spam away without thought.