I've found that the clarity of the line makes absolutely no difference with pike. They have poor eyesight to begin with, and are not at all leader shy. The color of your line in this case will make no difference.
That being said, I can't really say that I've had difficulties with largemouth or smallmouth bass in regards to line color either. Smallmouth tend to be a bit more leader shy than largemouth, but this doesn't mean that they require a clear line. I happen to use a ghost tip line (clear 15 ft sinking tip) for most of my smallie fishing, but I seriously doubt that not having the ghost tip would be hinderance in all but the clearest of water conditions.
Clear floating lines? I've never used them, but would only give them a shot in stillwaters. Moving waters that require mending need a line that can be seen so that proper mending adjustments can be made. This would be nearly impossible with a clear floating line.