Most likely, if you watched this, you watched the past seasons of Please Take My Brother Away. It has been a while since I watched season 4, so I started to refamiliarize myself with the show. I think it still holds up in terms of entertainment. The flash animation creates good and unique comedic effect (even though it's not traditional animation for anime, but whatever). The characters and their relationships are pretty much the same as they were in the last seasons. There is also just as much plot as there was in the last seasons (which is very little). In terms of comedy writing, Iwill admit it is a bit lacking compared to seasons 2 and 3. It had some funny scenes and actions like before, but I feel it is missing the whole escalation of situations. Some of the gags and scenes felt like they could've gone further with the jokes, but it ends before it could get better. What I liked from the previous seasons mentioned was the constant suspense of how much further they can keep doing their shenanigans, or seeing how much worse the situation gets.

Overall, there isn't a reason to not watch this season if you like it. It is a short comedy to have fun watching.