Upscaled releases are still better than the 2k, usually courtesy of color improvements changes, but it depends on the movie. Some are notable improvements all the way around despite being upscales, others aren't. Usually, I personally wouldn't consider it worth the massive increase in cost for an upscale over the 1080p unless there was a pretty significant improvement (rare), as opposed to native 4k releases that are commonly (though not always) significant improvements. Then there's also the different audio mixes you may not get on the 2k disc.

As an aide, what I don't particularly understand is why they can't (for movies shot on film or at 4k+) use a 4k DI and upscale any digital footage/effects as needed at that stage. Surely this would yield the best of both instead of having to upscale everything, in spite of some or most of it being able to be utilized at 4k in the first place. What I wonder is how often certain movies could've had their negative scanned at 4k, but receive an upscale because the studio was too cheap and already had a 2k DI.

Regardless, I do like that even for upscales, it offers the studios another chance to not screw up some movies that got poor quality 2k releases (like Predator).