I've been hankering for a EF 50mm f1.4 lens for around a year now. I do own the f1.8 lens.

My questions are - Is there a real noticeable difference between the two?

Is it usably sharp at 1.4 ? I know the build quality isn't great and I know there are rumours of a MKII (everytime I buy a lens a later newer model is released).

I would use the lens for indoor shooting of my new grandson a lot.