I finally had a chance to take some shots with the OM 28mm f2. Quite a bit of vignetting wide open, but it's nothing that can't be fix with a few clicks. When used wide open, it is surprisingly sharp and contrasty, without any glow/veiling that I would expect from old, fast lenses.
Walking and Talking by DannyLamNYC, on Flickr
Walking and Talking by DannyLamNYC, on Flickr