I need to get another secondary now. I'm wondering if I should get the 5 or 6 gal Better Bottle. I brewed my first batch in a BB 6 gal and I love watching it. I don't think I could use a bucket again. My thought was to buy another 6 gal and use for my secondary now, then later as another primary for multiple batches. My other secondary is a glass 5 gal. Is there too much headroom for a 6 gal secondary for a 5 gal batch?