We have several sequences which are too long to execute (test stand crashes during the initial load) using the preload option. These are often sequences with 50-100 subsequences which define contiguous tests to be performed.
If Test Stand had a 64 bit version additional memory would be a solution to this problem.
One of the major updates for TestStand 2014 was the release of a native 64-bit version. See www.ni.com/teststand/whatsnew for more information as well as a detailed whitepaper