Actually not a bad show. One of the better Disney shows in my opinion anyway. It's funny at times, interesting, and quite entertaining. Its mostly targeted at 7 - 14 years old so the humor may be bland to those older than that age range. I think the characters are quite interesting, and the show seems to get better as it progresses. It's not for everyone, that's for sure, but give it a try.
Sure, this show isn't perfect. There are plot holes, but then again, most of its viewers won't recognize it unless they do a detailed inspection of the show, which most people won't do. The thing about the humor is that it's kind of subjective. I find some parts hilarious, and my friend may find it boring. It depends on your sense of humor, really.
Also, to all those saying that they should use their time traveling ability for more creative things like watching dinosaurs or going into 3080, remember that this is Disney, not some high-budget Jurassic movie. They obviously can't afford to go all out with each episode. The reason why Mr. Peabody and Sherman have all those cool things is because its ANIMATION, and it's much easier to incorporate dinosaurs into animation than in a real-life Disney show.