Just performed a few tests with a script like your: http://pastebin.com/rJ57AB0a (I did the same, but in Python, using libclient)Results: 

• Official 6.0: Os times:  92.05 6.98 0.0
• pg84-next, cache disabled: Os times:  28.14 0.88 0.0
• pg84-next, using search_read(): Os times:  20.66 0.42 0.0

 and all that w/o optimizing stock.locations (not lately, at least).Script is at https://github.com/xrg/openerp-libcli/commit/30c15e59210682e5f32d