Most keurig units allow you to remove the portion upon which you sit your cup to allow for the taller travel mugs.
Yep, can be pricy but with careful buying about 50 cent per cup. Less than coffeehouse. Always fresh. If two people want different brew, strength it's easy. You can purchase units that allow you to choose size/amount of water that goes thru, so 6 oz, 8 oz, etc. If you open the lid and reclose the machine thinks new pod inserted, so you can run more water. Can you tell that I demo these? LOL You can get cider, teas, cocoas, all types of coffee.......nice! Convenient! The "classic" model allows choice of 2 water/cup sizes to disperse, 6 or 8 oz. In my area they average $120. This time of year many sales. These make the hottest water I've ever encountered....good coffee with that, just be very careful to let it cool a little.
I actually have two ot the Keurigs units and use neither. I still brew via drip. Also have two units that use different type pods. I can tell you that each of the K-cups from any Green Mountain product has 3 scoops of coffee in each. That seemed a real waste to me as I can put 6 scoops in my drip and get 9 cup pot (two K-cups). Of course that is 9 6oz cups, not a real mug...and the single units will make an 8 oz cup easily with one pod. I truly prefer the Grn Mt coffees as they are really good! In fact, I buy from them via computer and get the bags of ground coffee.
Just be sure to register the pot when you buy to be able to take advantage of their customer service should they fail.