The Viral will fit perfectly under your Assassin. This ball has the Vibe core (proven) and the revised coverstock (pearlized) from the BW Sting. The Viral gets through the front part of the lane with ease & has the great backend motion that all the Vibes had. With the Carbon Fiber outter core & Hammer's 3 year warrantee on this ball, makes a great buy for any bowler to add to their bag.

I really love the motion that I see with this ball when the lanes have burnt up & need something to turn the corner when playing inside.

Hope this helps your question...

Havent tried the Viral, but I have the same feeling about the vibe core.  My first was the Cobalt that I bought after they were discontinued.  The ball immediately made me a bunch of money on more varied conditions than I would have expected it to work on. 

I saw the Viral in action last night. This ball is superclean thru the heads, and makes a defined turn on the backend. Carries well, but I also noticed that it seems to carry better with a tight line on those light oil and dryish conditions.

I saw one guy shoot 279 with his standing about 35 out to 12 and back. And another guy was playing down and in, standing about 15, out to 5. He shot solid 230's back to back but lost a little carry along the way.

This ball looks great!

+1 on this endorsement.
I am loving this ball the more I use it.