I realise that there are many older questions addressing the general question of NUnit v MSTest for versions of Visual Studio up to 2008 (such as this one).
From VS2008 forward it is not neccesary to have MSTEST create directories anc opy the binaries in, just disable deployment, in 2010 thats the default but you have to set it in 2008
2010 MSTEST is faster but as its a generalised test framework that also runs load/web/UI tests there are compromises in the design that will lead to it being slower. Jamie Cansdale appears to have managed to get perf increases with the lastest releases of TestDriven.net's support for MSTEST