I've done well with some straddles, but I have also been burned in the past by them. You need a decent move in either direction to be beneficial. In the last 6 earnings the biggest same day movement was around 7%, followed by two 3% moves, and the others being under 2%
I dont normally play those strategies, but with the avg movement being 3% or under (at least in the last six earnings) I personally dont like that price action. Then again, I dont take a lot of straddles so I am def not an expert!