I just started on Tuesday.. Saw that mission that ended in like 1 day 12 hours or something. And barely made it (put ALL of my points into Engineers) with 2 hours to spare. So, I got the Prejor Scanner...

Now I'm almost done the thing for the Decrypted Data. What is it? Anyone have the Prejor Beacon? Is it the same as the scanner?

What would be more "valuable".. The data or the beacon? As I'm not levelling as fast now (the first 20 levels were pretty quick), I don't know how many runs of either I'll be able to do. Just looking for suggestions.

its different, and its well worth it.
as for "valuable" it would depend on your situation.

The decrypted data adds like 70 scan temporarily. This will allow you to find more planets and I would suggest waiting until your going to stack scan modules before using it.

The Prejor Beacon adds 75 cloak to a planet much like a chassis. It takes up one space on a planet and adds 75 cloak. This is valuable for keeping a good planet hidden from players.

Also Dan has said that when the Prejor arc of the story ends, he will unlock them all and let those who have not finished them finish them. If you have already finished them tho, I am guessing you wouldn't be allowed to do them again.