Per day being a key part of that. 30g at once is going to give a good chunk of people pretty severe cramping or a trip to the bathroom.

I don't think you can even do 30g at once in terms of mixing it. Even 5g in water it seems like theres some that will just stay crashed out of solution no matter what. I have done 25g over the course of a day though for a week long loading phase, and didn't notice any ill effects.

I think a lot of the anecdata on creatine is probably from people misplacing confounding issues to the creatine use. People in this thread are talking about heart palpitations or trouble sleeping. Stressful days at work are enough to trigger that.