55s - Open-limping AA at the early levels

Just wondering what people think about this. I used to do this a fair bit, then started always raising and lately I have been open limping a fair bit again. I can't remember ever limping with AA after someone has entered the pot but as first in I think open-limping has some merit.

I suspect most would say always raise AA no matter what but perhaps there are some dissenters?

If you do like open-limping then I'd be curious to know how often do you do it and from what position. My thinking is that I would never open-limp AA (or any other hand for that matter) from LP or SB. EP is dangerous if you get too may callers so maybe the best spot for this is MP?