Do this: close all aps first, restart, and then look at how much free memory you have (with all aps closed). What about if you do a 'free up memory' in sbsettings? How much free memory with just safari open (one tab)? How much free memory with safari open (one tab) after doing "free up memory"?
On an iPhone 4s: 278MB free after reboot, ~315 free after 'free up memory', ~110mb with only safari 1 tab app open, ~211mb after freeing memory after only safari open.
On an iPhone 4s: 278MB free after reboot, ~315 free after 'free up memory', ~110mb with only safari 1 tab app open, ~211mb after freeing memory after only safari open.