From what I've heard it's like if you were to get a 100% drop rate from Stella's fortune. <-- I agree with this after using them many times.
They are my favorite seal!
Yes, they stack with fortunes. See the level achievements thread: /forum/trickster-onl...ml#post1795457
In about 6 hours I collected 5000 chaos integer bytes .72 (5000 .72 bytes=an entire lvl @ 386!) using a drop rate seal and 30% drop rate acquired from stella.
When I was grinding there 2-3 bytes would drop from the monster, EVERYtime. Where usually only 1 byte drops, possibly, not every time.
A few days ago, using a drop rate seal, I farmed 100 stone balls in under an hour, it may have only been 30 mins.
I think the drop rate seal is worth it, no matter what you're hunting for.... unless it's uniques because I'm pretty sure it has no affect on them.
Oh, and it makes those painful questing areas (alteo, abyss, etc.) well... less painful
EDIT: Just to clarify - It doesn't mean that an item will drop 100% of the time, its like you got a 100% drop rate fortune. Meaning some items, from some monsters will
drop every time (like the bytes) but others won't.... it depends on the monster's drop rate for the item you are hunting (hope that makes sense)