and that includes the top of the line Onkyos, Yamahas, Pioneer Elites, Integras, and Denons. I have a Yamaha and an Onkyo and have 1080p upscaling turned off for both because my 1080p displays do it better. I've even done benchmark testing with an HQV blu-ray disc and digital video essentials disc because I'm anal like that.
One exception is maybe the super expensive Denon 5308 with the HQV Realta chip. Haven't seen the results of that receiver myself but I know anything less doesn't quite cut it. The lesser HQV Reon-VX chip found in many model range toppers is only equal to the image processing of a Pioneer plasma at best.
I'd say for any receiver budget less than $2k, you might as well skip 1080p upscaling unless you absolutely must have an all-encompassing video hub at the sacrifice of SD picture quality. Focus more on sound and other features in that price range.
larryV