Not sure how much SmokeFire experiences have been discussed in the forum, but I'll add my 2 cents. The other night at work, we fired one up and cooked about 25 brats. We cooked them in a couple of batches, and ran it for a couple of hours.
We had no problems with grease flare-ups. The smoke flavor was evident. For the last 10-15 minutes of each batch, we cranked up the heat, and got beautiful grill marks on the brats, along with a crisp casing that snapped with the bite. It can definitely put out some heat. There was minimal ash -- no more than you'd expect with a charcoal kettle.
We didn't measure, but the pellet usage didn't seem out of the ordinary.
And almost throughout the cook, there was smoke coming from the cooker. I've used other pellet cookers, where there seldom seemed to be smoke.
I think what people need to understand is that the SmokeFire is a different type of pellet grill. If you want a low-and-slow cooker that gives a small amount of smoke flavor, get one of the other brands. I've used some of the other brands, and sometimes they leave me wondering why I didn't just use my kitchen oven. If you want one that gives a lot of smoke flavor and can sear, the SmokeFire is an excellent option.
The key is to read the directions. And if you're worried about grease, use a drip pan. I usually use a drip pan anyway for fatty cuts like pork butts, simply because I like to keep my grills clean and don't want to deal with grease buildup.
Bottom line, I think I'm going to buy one. Hope this helps.