I prefer Septone Clear Coat (acrylic lacquer - also available at SCA) over the Duplicolor Clear. The Septone goes over the Duplicolor base coat just fine. Not had any compatibility issues.

I can't remember why I didn't like the Duplicolor Clear (it was quite a while ago) but I know I was happier with the result when I switched to Septone and have just continued to use it. Never tried the SCA brand clear.