Virgin Atlantic miles aren’t worth as much as other miles. However they do have strategic uses and I believe the single best one is ANA first class roundtrip from the Central U.S. and East Coast for just 120,000 miles per person. (San Francisco and Los Angeles is just 110,000 miles roundtrip, while business class runs 90,000 or 95,000 miles depending on the city.)
Another strong use of Virgin Atlantic miles is Delta business class between the US and Europe for 50,000 points each way, which becomes an amazing deal witht he 30% tansfer bonus. There are other award chart sweet spots, like Australia and New Zealand.