7 out of 10 points and not recommendedSmall, light, fast75mm eq not so useful on 1.5x crop, flare.
The 50 1.4 was one of the first lenses that I purchased for my 7D... (the other two being the Tamron 28-75 2.8 and the Sigma 70-200)...reviewed December 4th, 2005
And it is also one of my least used.
That is not to say that it is in any way, shape or form a bad lens. Its small form factor is very useful for social situations (less 'intimidation factor'), it is very fast...
The problem with the 50/1.4, Imho, is two fold.
First... the natural versatility of the the 50mm is really lost in a 1.5x camera... on the 7D, it becomes a 75/1.4... still a very respectable lense- but for portraits, not general-purpose... So its the perfect low-light portrait lense, right?
Not so fast, because the other problem with the 50/1.4 is, at least my copy (Type I), is flare... not so much veiling flare, but point flare of light sources in your image are VERY prominent... any light fixtures or point lights (landscape or indoor) are rendered in almost perfect detail 180 degrees away from the image's center in ghostly green... this makes the lense practically worthless for any type of night shooting (unless you go to great lengths to keep any form of light source out of your image)... Perhaps its just the coatings on my older copy have worn out - but its really sad - the fastest lense in my bag is worthless for the type of night shooting that fast lenses are good for...
So whats left? portraits? Yes, indeed its a good bright portrait lens- but then what's the point of the F1.4? In fact, my Tamron 28-75 F2.8 is every bit as sharp throughout its entire range, gives me more portrait flexibility, and since the 50/1.4 is near worthless at night - the added speed isn't even an advantage...
This is not to say, in any way that the 50/1.4 is a _bad_ lense... in fact, it has spectacular image quality, and with very careful framing can take wonderful low-light images wide open... My biggest problem is that, while it is a wonderful optic, its few downsides are such that they cancel out all of its advantages, leaving a lense that spends far too much time in my camera bag and not on my camera...
In short - a great peice of glass...
But save your money - buy elsewhere.
For General Purpose Prime:
Sigma 24/2.8 - cheaper, same size, better FOV, no flare
Anything 36/1.8 - 50mm eq
Minolta 36/1.4 G
Tamron 28-75/2.8 - More versatile, better in low light (because it doesn't flare).
Minolta 85/1.4 G - Better Portrait length, better image quality.