I have a Bunn MC and MCU, and use the interchangeable drawers all the time. I have used several renditions of Rogers family coffee (the ones with the mesh bags) without any problems. I also have an old Keurig model 30 that just keeps running no matter what happens to it, and a Vue that I just startign using this past weekend.
The Bunn MC + drawer brews K-Cups with more gusto than the old Keurig. Toward the end of the cycle, steam starts coming out and sometimes there is a little splashing / spillage. I more appreciate, than am annoyed by this, because I believe that I am getting a better cup of coffee from the Bunn.
The basic Bunn MC isn't flashy. There's no fancy LCD screen that shows the exact water temp and your heart rate. But they work reliably and are backed up by a company known for excellent customer service.
So far I've used regular K-Cups, various OneCup brands made by Rogers and the newer (to me) Real Cups (Martinson, Marley, Brown Gold, et. al.) in both the -30 and MCU drawer. Never had a problem with any of them. Of course, you'll also be able to use ground coffee and pods, which you can source from all over the world (which is half the fun of all this). One non-fancy coffee that I like from the MCU, is the humble Seattle's Best #4, available on your grocer's shelf. I like dark roast, and this coffee from the MCU will give you a bold, flavorful cup of coffee. It's only available ground, and it's almost a little too fine for this machine. I clogged up the head once, but that was out of about a hundred cups - and was solved by putting the grounds drawer (with screen separated) through the dishwasher. When I'm grinding my own beans, I go a little coarser - not much, call it a medium ground. I use filtered water from the fridge - one cup at a time.
I fully support your desire to use these more environmentally friendly (not to mention cheaper, I mean, less costly) pods. Check out the Rogers Family Company Coffee & Tea blog
. They are good people. One of the founders travels the world, meets with small farmers and builds schools in their communities. Recently, their philanthropic focus has shifted to planting rust resistant trees so small farmers won't be wiped out by failed crops.
All the best, -- Dave