As Aroy said regarding flare, the 58mm is beautiful in that area. Better than any other lens I've ever owned. But, and it's a big but, the autofocus can be truly rubbish in daylight situations, far worse than my 85mm f1.4 or one of the class leaders, the 24-70 f2.8.
And if I want to use it wide open in daylight then the softness is legendary. You may say when would I want f1.4 in daylight? Example; I was shooting outside Keble college in Oxford, for a local magazine and wanted to truly isolate the Dean of the college from the muddled surroundings of the city. The image at f1.4 was so soft that it was unusable. Thankfully, I'd taken a few at f2.0 and several using the 85mm f1.4g wide open, so I got what I wanted.
I struggle to understand how they can produce a great wide open lens like the 85mm but not carry it across to the 58mm?