The ridgid summicron has great character, creating an almost etched looking 3-D photograph. Flare can easily be a problem. Relatively heavy.
The later model tabbed Summicron is wonderful in handling and for producing a sharp, well-balanced photo. Very lightweight.
The hexanon is fantastic also, and very well built. I often keep the built-in hood collapsed and use a screw in hood, which provides more protection, but really I have not had any problem with flare with this lens.
All of these are in the price range, and all are excellent. Among these, I would choose based on if I wanted the character provided by the rigid. If not, I would be happy with either of the other two, without a doubt.