I think it really depends on your collection. My one puzzle is in Brownie, and I can use it a ton because it goes with everything. But each time I see a special edition I regret my choice a little haha. Knowing full well I would use it much less. I say if you need a workhorse, go single color. If you want a fun addition to a pretty solid collection, go special edition.
As for usability, it’s an incredible bag. One note, it holds slightly less than you’d think purely because the opening is a bit smaller than the width. But you can finagle a bunch into it.