BJL, very good.
I will likely buy this lens if it is as good as the Shorty Forty. I have found that it is very convenient to have a lightweight "just in case" lens with you if you are carrying multiple primes or are working mostly with a heavy telephoto lens. My current full frame lenses in the 50mm range are old AIS Nikkors, the micro 55 f/3/5 and the 50 f/1.2. Both are surprisingly good for old designs, and weigh about 2 to 3 times the Canon Nifty Fifty / Plastic Fantastic.
Good business move for Canon - inexpensive gateway drug to prime lens-dom.