Monthly's i don't pay too much attention to but like to know where they are.
Accuracy ? Its useful for me to know direction and rough levels where price may find S&R - i won't trade to point.
Weekly's are more crucial for me around the 50% levels.
5 Day 50% are very handy for rotation. 5 day high/lows are invaluable in a couple ways. Last night was a fair example (5 day high level combined with a static resistance level). Another is with extreme market moves over a few days. Range is another as well as patterns (for all).
Generally find the indexes i observe have similar relations with the dynamics, congruently.
Under differing market conditions they will be useful in slightly different ways too as you have pointed out.
