Sorry dude my intention wasn't to make you doubt your decision. The way I see it is you're the size of guy that could enjoy both sizes. If you will basically only ride these when its a pow day, then the 185 is probably the right decision. On pow days, I was perfectly happy with my EP pros and Bentchetlers. Its just that I ski in europe and have a 2 ski quiver. One pair is park skis (Lizzies but probably something narrower this winter) which have next to no edges underfoot, The other pair is my pow ski. The result was I ended up skiing groomers, slush/crud days, tight chutes etc with less perfect snow etc on these fat 183-185s. Which while do-able, I found tiring and un-necessary, especially since we didn't get much snow last season. Thats why I'm looking at going a bit shorter for this year. I haven't skied the Opus by the way, so take my opinion with that in mind.
Ski length is just preference though. I'm sure you will love either length. 185s are gonna be floatier, less tip dive etc. There are lots of benefits either way really.