Bob,
No sir, no need to profile. I have applied this to smooth coatings that were clean and dry, and it bonded like glue. This product is also suitable for properly prepared steel, the pigmented version is more well known.
The first coat of Rexthane will soak in to the smallest of pores, and the second coat will bond to it. However, there is a clear primer available for this product. If you are worried about the product not having enough bite into your bare concrete, you could grind, prime, and then apply the product. With the amount of time and money it would take to do that system, I would recommend grinding, densifying, and polishing.
We consider this product the best choice if simply cleaning the concrete, and applying a clear coat.
Eric w/ GFE