Got this lens yersterday and I'm impressed.
Took a few pics to compare it to my Tamron 28-75 2.8 zoom.
The 40mm is a bit sharper, has better contrast and bokeh, and is sharp from corner to corner unlike the zoom.
All pics are unsharpened RAW pics straight from camera, xcept the last one which has a bit of sharpening.
I only had mine for about a month or two. I was very impressed, but I have a 17-55 f2.8. The 40mm was great, but I decided the value would be better placed in a tele zoom. One day I hope to have it in my kit, again.