I got command rank 300. From 120 tier 3 crates:
5 legendary 242 - 3 useful (main hand, offhand, bracer) - alacrit relic and one more offhand
11 purple 240 - (bracer,belt,gloves,legs,2 implants, ear and mastery relic) - rest duplicates
so my legendary drop rate is around 4.2% (2,5% useful)
and purple 9.2% (6,7% useful)
i read somewhere that after 300 chance for good item is better.
From 15 packs so far:
0 legendary
3 useless purple i already have
best part is that from 315 crates there was 0 power relic
on the other hand i got many useful schematics. I can almost craft full 240 gear to my dps, heal and tank alts and
my credits went from 10M at start of 5.0 to 1100M right now.