We actually evaluated couple of service virtualization options - CA LISA and IBM RTVS.

We did go for RTVS as the organization had a tie-up with IBM for other software too, hence commercial it was benefits for us. Also, RTVS has a free one month trail, so we could had a tool experience before we actually purchased the license.

Also IBM RTVS is far cheaper than CA LISA which provides similar SV solution.