welcome pac, it'sso nice to have a new person to talk 'keurig' with. regarding the water tank, i personally find it much easier to bring the water to the tank, than the other way around. i just remove the top, and pour bottled or tap water directly into it. as much coffee as i drink, i'm doing this several times in the course of a day.
i'm glad you mention the donut shop coffee blend. it is described somewhere as being a fresh, no-nonsense coffee most like you might be served at a diner. i agree--unpretentious, straight-up good, honest, no-frills coffee--especially good in the donut shop xtra bold. i'm not surprised at your not being impressed with the breakfast blend. i bet it's popular with those 'occasional' coffee drinkers though.
i'm not familiar with the keurig model you bought, pac. what size is its reserve water tank? i think 60 oz. is the largest tank available. i use the mug setting on my keurig, 10 oz., i think. but you will probably get a more intense brew using the 6 oz. setting twice. all of that, the size and coffee flavors, is just a matter of trial and error.
i hope you continue to find more good and fun things to enjoy about your keurig. since you will be using your own coffee brand(s) you will be missing out on one of my favorite keurig excersizes--that of trying and selecting different and new coffee blends. i'll be interested to hear how you like using the 'my' k cups, and how well they work. have fun with your new toy, pac....