I'm retired FERS, I put mine in L2015, (which is now all G) then moved it to L2020. It's made up of all the other funds, but mostly G, so what is the difference then if you put some in G, C, I.... you can select a L fund that suits you. My advice is to leave it in TSP until you have to start drawing at 70. The admin cost of the TSP funds are the lowest you will ever find, hands down. Some info>
http://www.bogleheads.org/wiki/Thrift_Savings_Plan