im 6 foot 4 inch and 280 #s needless to say im a big guy. i skied the 184 mantra at jay this year in about a foot of powder and really liked it. however, would it be worth my money to upgrade to the 191? I am an advanced/expert skier doing 70/30 % on/off piste on the east coast. what do you think? would the 191 be too much ski for everyday?

At 6'6" and 275 lbs, I completely understand where you're coming from. I bought the 191's this winter without demo-ing and considered the 184 at the time. I'm an expert skier that only hits up groomers when the girlfriend is around. I have never regretted purchasing the 191's. If you can sell your current pair to significantly subsidize the upsizing, then go for it. The additional stability/lift is worth it in deep pow and at speed on groomers. You'll be truly unleashed on untouched swaths of corduroy with the aggression of an imposingly-nicknamed Austrian, especially if you're on-piste most of the time. My only words of warning are to just be ready to get technical in narrow chutes (think entrance to Corner Pocket at Fernie), and tight trees because it's a lot of ski to crank when you're staring down runs that skiers on average length skis are having second thoughts about.

As you said you are a tall guy at 6 foot 4. You could go with 191 because although that would generally be considered a lot of ski you are tall enough to handle it. In fact, you would be a little taller than the 191's so I think they would suit you fine. I think that for a guy your height the 184's might feel short. Again, given your height, with the 191's you would have good stability at speeds, nice float in powder, and still be able to make quick, tight turns. Hope this helps!