I know that Splash must be easy to use and I agree that. But there's few functions which absolutely, I repeat: absolutely, must be added.
First of all to make video look much better is denoiser / noise filter / noise reduction. Modern studio cameras still have a problem with high noise level in low light. F.e. the movie "Black Swan" (2010) is highly noised and in hd it looks not so good.... Most of HD TVs has such filter. What is more, if we turned noise reduction off in HD TV and we compared it to modern PC monitor, then we would notice that PC screen shows noise more intensively than TV. So this options is highly needed. The amount of filter should be adjustable like other options (light etc.)
Second option is colour correction. A lot of older movies (1995 and older) has not natural colours although they were digitalized and stored in HD. For example most popular films of 70s and 80s has an 'admixture' of red colour. Faces are too red and sky isn't cyan-blue but rather violet(magenta)-blue. However, I also saw some movies which were too yellow-green. Anyway, there should be a single slider which would change overall color tone (Hue) similar like in Photoshop but with more narrow band. I would enjoy it very much.
Last option or rather an improvement is case of subtitles. They should display a proper charset. As soon as I see it can't (actually polish). Also a position of subtitles should be easily adjustable f.e. by dragging up / down by mouse.