Good summary on the subject:
http://www.compcams.com/technical/FAQ/LSAproperties.asp
Some of the engine discussions regarding LSA and EFI also has EGR in the mix (on stock engines). With an EGR valve, you don't want or need a smaller LSA since it's the EGR valve's job instead of having natural EGR. On stock engines that expect EGR, this could cause tuning problems.
Case in point. In the 90s, GM came out with the LT1. This engine had an external EGR valve. Then the hotter LT4 came along, which did not! The LT4 was the same engine, just hotter heads, cam, and intake. GM designed the LT4 cam to provide enough natural EGR, that an external EGR valve was not needed. And somehow they convinced the EPA of this as well!
The other generic rule of thumb that I've always known... a larger LSA is better for higher RPM use. But if you want low-end torque, it's usually good to have a smaller LSA. I say "usually" because there are other factors of course that need to play nicely together.