When you drive with a spool it is very obvious and noticeable on turns. When you drive with a posi unit it has a limited slip which makes turns much nicer than a spool and we tend to get used to that as the "right" feel.
When you drive with a Wavetrac, they only way I can describe it is the differentiation wheel to wheel is absolutely invisible to the driver. It feels even better than an open rear end because of the continuous torque re-biasing based on the road surface conditions under each tire.
The effect in the driver's seat is a sense of very complete control and predictability. As you probably have already guessed, I am a pretty big Wavetrac fan.
Ed