Mostly I'm voting with my 100% power on any articles I read and think is good. I like to give the proper support with what I can. Anyways I'm not reading 10 or 20 articles a day, mostly between 3-5. Leaving me with plenty voting power for comments as well. On my Own posts I like to also give 60-100% voting power to those that contribute with quality comments. But of course I cannot keep that up if my followers base grows.
I see reason why whales don't use 100% simply because they have more value to their votes and even 5% is quite a powerful vote for some of them. If I had that much steem power i guess I would be going with that strategy as well but also reward specific outstanding posts with a big fat vote.