Am I crazy? Considering OM-D over K-5II...

Jolly Oly wrote:

There is no cheating there.

"As we saw in an earlier article, the ISO definition used when you take photographs is based on the brightness of the resulting JPEGs, not on any inherent property of the sensor. Which is something to remember whenever you see anyone talking about manufacturers ‘cheating’ on their ISO figures."

I would suggest reading about this topic, you can start with THIS Richard Butler's article.