On green field deployment, it is recommended to go with the latest IOS available.
If the switch was already on production and the IOS meets all the features needed for deployment, I recommend remaining with the current IOS unless there is a upgrade trigger (new hardware/software feature or service impacting bug).
Make yourself familiar with the Release Notes. It contains service impacting bugs and what's new on the IOS release in term of software and hardware.
http://www.cisco.com/en/US/docs/switches/metro/catalyst3750m/software/release/12.2_50_se/release/notes/OL18264.html
http://www.cisco.com/en/US/products/hw/switches/ps5532/prod_release_notes_list.html
HTH,
__
Edison.
