I'm a huge Osomatsu fan. So when I give this a 2 star review, it hurts. When I first heard about thus anime getting a dub, I was worried but willing to give it a chance. This show is a prime example of how hard it is to translate and dub a heavily Japanese centric comedy. To say this show has puns and wordplay is an understatement. Unfortunately a lot can't be fully translatable because of that. So instead of translating and leave it for the audience to understand it or not, the dub opts to write new jokes and puns for American viewers. They can be a minor hit and major miss. A huge miss is just peppering random cursing when the original added it when it was appropriate. A scene that suffered this problem was in the first episode where Osomatsu crashes Choromatsu's meet-and-greet with Nyaa. The original was funnier because every other word was bleeped making it sound really vulgar. The english version has Osomatsu's rambling unbleeped/uncut. It definitely trades the comedy for edginess.
Another problem with translating is losing intention of words. More than "lost in translation", how someone says something may change your interpretation of what is being said. The worst who is affected by this is Karamatsu.
The voice acting is a mixed bag. The voice talents of Iyami (Keith Silverstein) and Chibita (Alejandra Cazares) are great. Everyone else is either miscast (Michael Sinterniklaas as Jyushimatsu) or trying too hard to be cartoonish (the uncredited role of Dekapan). I was quite interested in how these talents would play their roles when I first saw the announcement, because I love a few of them (Michael Sinterniklaas will always be my favorite Leonardo) but I'm disappointed. I don't fault any voice talents for playing the roles they are hired to do. I do blame the voice director though.
I could go on, but I think my review explains enough of my problems with this dub. Please wait for the english Blu-ray release early next month. It will have the Japanese (and English) dub with English subtitles. It will also have bonus shorts which were not translated by Crunchyroll on it.