I go for platinums but have a decent amount of 100% too, the only problem with 100% is that it doesnt boost you level up by much due to limited trophies. So sometimes putting 20hours for a 100% doesnt seem worthwhile, as most of the games nowadays can be platinumed in the same timeframe, if not less.
But i like both anyways, its just that the 100% dont seem much rewarding except of portraying you as a completionist.
Many times people have exclaimed over the number of platinums someone has, I have never heard anyone talking in awe about someone having mnay 100%. Thus the competitive aspect that people associate trophies with, seems to get a bit lost there.