It depends what you're shooting. I had the DA35 when I picked up a Flek for £10.99 (granted, it has a wee dent in the filter thread). The Flektogon has better handling and construction, it focuses closer than the DA35, and has a nicer bokeh, in my view. I have not had any issues with low contrast, in fact I thought contrast and colour rendition was better for the Flektogon. I shot a few comparison shots over at Flickr:
https://www.flickr.com/photos/antipattern/sets/72157632642710069 and there are some more pictures taken with the Flektogon/DA35 in my stream there, too. For street photography I actually preferred the Flektogon, too, as the focus is less fiddly and actually stays in place better than the plastic fantastic DA35. However, I was always a little gutted about the lack of EXIF-data in the files, and the annoying adapter, that would get stuck to my camera, usually when I left the metal thingy to unscrew it at home.
In the end I ended up selling the DA35, albeit for a DA40. The Flektogon still makes it onto my K5 every now and then, and I recently used it with my MX-S on film. But usually, I go for something with autofocus these days.
It sounds like I'm slagging the DA35, but I have to add, that it was my first digital prime and some of my favourite pictures were taken with it. When I first got it, I was blown away by the quality difference compared to my other lenses. It's a fine lens. In the end it boils down on your usage, really.