I like lighter discs - usually under 170, with several 150 class and a couple of Blizz in my bag...but I prefer beefier putters.
The first APX I started to hit consistently with happened to be a 173 (it's not like I consciously selected that weight). I tried a Swirl at 168, convinced that 2-3% one way the other was insignificant - wrong! It genuinely felt different in my hand - if nothing else, it flows from there. Since then, every APX I've purchased has been 173.
My Challenger's (used for upshots) is 175
Two facts to keep in mind:
1) The closer you get to the pin, the more accurate you need to be.
2) The greater the mass, the less effect the wind will have on it.
Draw your own conclusions.