You can get a fully functioning demo from
http://ikmultimedia.com.
After about ten seconds with the SVX plug-in, I knew I had to have it. This is after owning Sansamp products for years. I even got Amplitube 2 as well.
After trying virtually every amp sim out there (Sansamp, Line6, Guitar Rig 2, Waves GTR 2.0, Revalver MKII, the list goes on), IMO the IK Multimedia products are superior. They use less CPU than the others as well.