I've got a different model MasterBuilt digital. Holds temp great, but I've had issues with keeping my chips smoldering. There's no bottom venting and it seals tight so chips start to smolder then die out. I've used the hinged closer to allow my door to stay open just a crack for a little circulation. I also just drilled some holes in my chip holder and just above the chip holder. I don't know if this will help or not. I haven't used it since I did the drilling. I've also pulled a couple pieces of once burned charcoal out of one of my Webers, lit them, and placed those in the chip holder - that helps the chips smolder a little.
My MasterBult is electric. Insulated and very air tight - that is why my chips die out. I've had very good success with Luhr-Jensen. I've had two over the years - each lasted about 12 - 15 years before the heating element burned out. They were very good little smokers. Only problems were there was no temperature control - they were factory precalibrated to operate somewhere, I think, in the 165 - 185 degree range - ideal for smoking fish and making jerky - and they were thin metal with no insulation making them hard to operate in cold weather. Think Luhr-Jensen finally did bring out a thermal wrap for insulation in cold weather. I used a welder's blanket that I got from one of my wife's company's suppliers.