The Keurig K-Supreme does not have programmable brew strength and temperature settings, while the K Supreme Plus version does. The K-Supreme Plus also has a larger water reservoir tank which holds 78 ounces, whereas the Keurig Supreme has a 66 ounce water reservoir.
As far as brew sizes, both the Keurig Supreme and the KSupreme Plus offer 6, 8, 10 and 12 oz. brew sizes, however the Plus model also allows you to brew a smaller 4 ounce cup.
The Keurig K-Supreme Plus brewer also has a digital display screen and a stainless steel wrapping for a modern, elegant look. Finally, the K-Supreme is a bit more compact and lets you choose whether to install the water reservoir on the side or the back of the machine. This may be a worthy tradeoff if you have little counter space.
The K-Supreme Plus SMART is the newest model and is a “smart” coffee brewer. Unlike the Supreme Plus, the K-Supreme SMART version has what Keurig calls BrewID technology. This is supposed to know which K-Cup pod you inserted into the machine and thus will automatically adjust the brewer’s settings to the most appropriate for that brew.
The other difference is that while the K Supreme Plus has 3 temperature settings and 3 strength settings, the K-Supreme Plus SMART model has 6 temperature settings and 5 brew strength settings.
The K-Supreme Plus SMART is a slightly upgraded version of the K-Supreme SMART. The Plus SMART brewer model has a larger 78 ounce water reservoir tank, while the SMART version has a 66 ounce water holder. The K-Supreme SMART model allows for 4 brew cup sizes (6, 8, 10, and 12 ounces), while the KSupreme Plus SMART allows for all of these plus an extra 4 ounce brewing size option. Finally, the dimensions of the two models are slightly different, with the K-Supreme SMART sizing up at a 12.2 inches tall, 7.9 inch wide, and weighing 5.8 pounds. The upgraded K-Supreme Plus SMART on the other hand measures in at 12.4 inches in height by 8.3 inches wide, with a heavier weight of just over 8 pounds.
The Supreme Plus Special Edition brewer model is a newer offering, typically sold at select retailers such as Costco. The Keurig K-Supreme Special Edition model allows you to choose from among 5 different strengths and 5 temperature options, whereas the regular K-Supreme Plus coffee maker only allows you to select between 3 strength options and 3 temperature settings. Apart from this difference, all other features appear to be identical.