Yeah, that Katadyn BeFree is definitely on my wish-list. Katadyn has been a top brand for filters for a long time, but this BeFree really looks simple, cheap, and effective. The Sawyer filters are still more versatile - so I probably won't drop them all together.
I'm not familiar with the Hydrapak Seeker. I do have a few of their soft flask bottles. Pretty neat bottles, however I don't end up using them very often. They were called SF500 and SF750 when I bought them in 2014.
I'll have to check out the Seeker model.