I'm not sure why people think buckets are easier to store. Just because you can nest them together doesn't mean you SHOULD. I've bought a lot of homebrewer equipment leftovers off craigslist, and any time there's a bucket included, they have it packed full of junk (caps, capper, ingredients, whatever). That bucket will never hold wort again, not for me.
So, in my brewery (garage/patio), buckets take up as much space as a betterbottle.
It's easy enough to see into a bucket by shining a flashlight through the top (to get a rough idea of where the krausen is at). Buckets are easier to clean too. And cheaper. And re-purposable if you decide to retire one.
But I still like to watch my beer fermenting Better bottle wins!