Are you racing with these?
Are you strong enough to flex crank sets?
Omniums are certainly a great value, but they aren't considered the best track racing crankset. Then when you figure in the cost of upgrading the bottom bracket (around $100) the value isn't that great. It becomes a good value. They are popular on the street fixed gear scene because they are the most inexpensive race-spec crankset on the market.
Despite being one of two track cranksets using external BBs (Rotor being the other one) very few use SRAM Omniums. Dura Ace seems to be the most popular standard cranks. SRM (which uses the Shimano Octalink BB) is also very popular for those who are into power data.