Let us rationalise a bit.
I think it is safe to claim that Muhammed was a wise man. He got millions of people to follow what he said. You can not accomplice that when you are stupid.
Now lets think about heaven, and you would want it to be. Would you really want heaven to be filled with virgins eager to have sex with you as often as you want?
My answer on that question would be no.
If I had to describe heaven then it would be a beautiful place with lots of nature and the people I love would be there.
I think it is safe to say for myself that I am not stupid. Muhammed wasn't stupid either. Would he really have made up a heaven filled with virgins, or would there have been a different explanation why it says so in the Qu'ran?
It sounds a bit like a trick from the devil orso to me.