I almost always give everything to the devs, with maybe a dollar or two to HIB to cover things like hosting, dealing with Steam, etc. If I were going to donate to EFF or Childs Play, I would do that directly, not as a way to self-justify paying less of my money to the developers that put a lot of hard work into the games I'm buying. But hey, working in the gaming industry might make me biased...

I usually give most of the money to charity. While I have purchased the majority of the Humble Bundles, I don't actually have time to play games. For many of the bundles, I've not even bothered to download the files. That's how I rationalize it anyway.

Mostly to developers, but man are those sliders annoying. It took a lot of fiddling to get all three in line. Some option which would let me under or over allocate temporarily would have been a huge help, instead of this one up, that one down, that one back up, that one down again.

you can directly edit the dollar amount in the field to the right of the slider, and it will bubble-up to the total.

I went 75% developers, 25% humble on this one; I'm usually much closer to 50% devs / 30% charity / 20% humble. My reasoning being this is an above-average bundle IMO, and I want to see the developers rewarded handsomely so that more critically-acclaimed games will come to the bundles.

For HIB 4, I did the same thing you did. But this time I think they're doing a good job at selection (and I like the EFF), so I went default split.