The D+ is not actually upscaled. It uses the original unaltered source without the small losses in quality which always come along through the DVD encoding process.

As for upscaled versions, animation upscale is something that only destroys the original picture / detail if not performed manually on the source material. This kinda’ sums up my opinion when it comes to upscaling in general.

So yeah, I will always go for Standard Definition instead of HD if there is no actual work done to the film masters / source.