sigh. the purpose of any training aid is to improve. the idea that one needs to spend a lot of time getting 'smoother' is erroneous, at best. What emotion do is allow you to train long and hard without being locked into a rigid frame. It's a much more natural way of riding, and as a result in general one can typically ride longer with less mental and physical discomfort. The float allows one to change positions, stand, sprint, etc while riding more naturally.
I've got two sets of them, and have ridden 100s and 100s of hours on them.
And no, I couldn't get enough resistance from regular rollers to do what I just got done doing.