i'm having a similar problem of getting reduced to either 0 or 1 fps, but
only when i open the character info screen, and so far, no other time (just laggy otherwise) although i don't remember seeing anything having to do with any add-on (other than built in from blizz) in my bugsack, but it's happening consistently, and makes it difficult to swap out gear when i get something new. i'm forced to right click on an item in my bag to equip and just try to remember what i have, as going into character info to get equipment manager to save is horrendous...it sticks forever
i updated my nvidia card driver the other day, and at first i thought it had helped, but it seemed temporary...the reboot prob cleared whatever is causing the massive lag/standstill, but it comes back anyway. i still have the usual amount of available memory, so for now, i assume there is some conflict with a recently updated add-on that i haven't had time to isolate yet. if i come across any lua errors, i will post more info...