Zagsy has little to 0 value IMO, there are still so, so many names like this, with these kinds of letters, available, I run across dozens each day in my searches.
Proob is quite good though. To find all premium letters in a one-syllable name that sounds exactly like it is spelled, and can have few alternatives/typos, is becoming quite rare. Add to that it has a nice solid sound to it, rather than a lot of LLLLL we see being regged where you just go "that sounds like no one would ever want it". Proob is in the good zone of brandability; not a hot hot hot zone, but good zone, so I'd give it some value, in the mid xx range for now.