me too,i had android and when i had too many apps installed..,it began to lag...but here i didn't noticed any lag when having only a few,or almost all the memory full(btw,i've got a lumia 720 -8gb- free space,and now i have just around 1,5gb free),i have an sd card,but it's class 4 but i use that space just for media,and things that don't 'stream' with the phone's memory.Just wanna know..
