Don't have a Keurig, but I have heard both: that it is awful and almost undrinkable, and that they are amazing. The folks I know who tend to think they are amazing, are the folks that use them for something other than just coffee. They will drink the coffee, but also use them for tea or hot cocoa. So they are more versatile. Also, they tend to be "onlies" (they are the only one in their house who drinks coffee, their spouse is a non-coffee-drinker). We tend more toward the "coffee snob" bunch, though we aren't true snobs (we don't roast our own beans, or anything like that--though we know some who do--- but we don't drink gas station coffee either.)
If you are having a problem with the burnt taste, get a maker that does not pour into a carafe that sits on a burner. That should solve most of it. We had one of the Hamilton Beach ones that pours directly into your cup (makes a full 12 cups, not just individual cups) and has no carafe at all. That was great, but as with any maker, over time it stopped working so well. I think the heater eventually fails to get the water to a high enough temperature. Then we went to a Cuisinart Grind/brew with a stainless steel carafe. It was fantastic. (noisy, but great!) It never tasted burnt, because it did not sit on a heating element. But, it only made 10 cups, so was annoying when we had coffee drinking company. Eventually, it too began tasting "off" and again I think it was probably the heating element. Right now, we have a KitchenAid machine. We grind our beans ourselves. This machine gets the water really hot, and makes a fabulous cup of coffee, but it has a glass carafe that sits on a heating element. If we don't want the 2nd cup to taste a L. burnt, we have to pour it into a tempered stainless steel carafe once it is made. Then it stays tasting great. I also will not drink coffee out of a travel mug lined with plastic. That affects the taste too. I have a ceramic travel cup from Starbucks and my husband uses double insulated stainless steel.
Back to the K cup situation. My husband's theory is that many people are not accustomed to the strength of the brew the machines make, because most people don't use the "instructions" on the label of coffee when they make it at home. We do. So our coffee is very strong. My dad says it can get up and walk across the room to your cup. :) I would imagine that all the Kcups are measured to the strength that most coffees have on their labels, but most people don't use that much, so it is stronger than they are accustomed to. Maybe that is not it, but it is hubby's theory anyway. He had a cup from a machine at church and said it was "okay". If you are ok with an ok cup, then if it is more convenient for you to continue with it, go ahead. If it is more hassle and work, then return it and stop bothering.
Happy New Year!