For me, if an engine has smoke it is a necessity when it is running by itself. When multiple trains are running, and you attention is drawn between several engines, the smoke becomes much less important.
I am sorry I offended anyone with my curt response.
Sometimes we just like to blow smoke in this forum. It's part of the fun! For some.
Being new, I'm actually a little curious about the subject, so I enjoyed the discussion. I'm thrilled with the smoke and sound, that and digital control are what brought me back to the hobby. As much as I hate paying for smoke oil, I can't imagine running a steam engine without it. I've tried turning it off, but quickly turned it back on, it just wasn't the same without it. It may lose it's appeal after awhile, but for now, it's fun.
Originally Posted by G3750:
Rusty is correct. On the Pennsy, such a dirty smoke cloud would get someone reprimanded.
As for smoke - around the Christmas tree this year we exclusively ran (for the first time in my memory) a Christmas Beep diesel. 
But, I too have found the smell too much and have gone to NADA (unscented) smoke fluid on the Panhandle. I have 6 locomotives and a steel mill (2 industrial stacks) contributing to the air pollution! And I really like the look of steamers putting out smoke. The excellent photograph was taken by Mike Mattei in January 2011.
George
George I keep looking at that photo and my god that sure is a beautiful train especialy with the smoke. Are there more photos of that somewhere? I may become a convert to smoke 
For those members who have respiratory issues, I can understand why any smoke output could be an issue. For those of us who are fortunate not to have these problems, there is nothing more impressive than an engine with good smoke output. Also factor the Vision Line features with blow-down effect and the steaming whistle, the smoke option is a real plus.
When I built my train room, I installed a jumbo ceiling exhaust fan that clears out any smoke build up very rapidly. So visitors to the layout have never complained about the smoke feature but rather enjoy the effect.
Count me in the "like smoking engines" group.
Thanks, Passenger Train Collector, I need to include an exhaust vent to my list of things needed for my future layout because it’s been mentioned a few times. Up until this thread, I never even thought of it.
The last time I had a smoking locomotive it was because of a fried electronic component. The smoke was coming out of every opening except the exhaust stack. Since I model the Penn Central the effect was pretty prototypical. I wish I would have thought to grab the camera and shoot a few pics.
Tom
