It does tap itself for its effect so Collector's Vault only benefits once per turn unless you have ways to untap it before your normal untap step
I imagine you reach for blues many Thopter generators since small flying bodies are the perfect recipients for a large buff
Exceptions made on a case by case basis
A Few Additional Twists for Good Measure Between -1/-1 counters, proliferate, modified creatures, cards that remove counters, and cards that just care about ANY type of counters, this weeks decklist had a lot of weird mechanics that play together, which always yields fascinating results, like Danny Pink and Denry Klin, Editor in Chief (neither of which made the list since they can add +1/+1 counters, but wouldve been amazing without our self-imposed restriction)
Here are the percentages: (note when I say "rare" below, I mean rare or mythic rare) Common, common will happen 49% of the time
The ability Im most excited about with Vivien Reid is the minus three ability