How about criteria for this?
IF:
You own more un-built kits than completed you are a collector. (me)
IF:
1/2 or more of your kits are finished you are a builder.
To make my situation more accurate I would have to add 30-30 to my affliction, that is 30% of my kits are 30% or more complete.
That being said I would be a 70-30 modeler.
Confusing? A bit... It will be interesting how others reply...