Omni group tires are hit or miss. They make some actually very good summer tires and all seasons under the radar brand name but also some less than good stuff too. I'm not sure about the corsa branded tires, but check simpletire and 1010tires for reviews as both sell omni group tires.
Also check to make sure the tires are rated correctly on those sites. My radar summers were listed as all seasons on simpletire. Omni groups site is actually pretty good for info.