These ambitions are impressively realised by the 40B550's picture performance. For it: a) gets much closer than I'd expected to the excellence of Samsung's step-up B650 range, and b) outguns easily anything else of a similar size going for the same sort of puny money.
Particularly unexpected is how clear and sharp its images are, as it copes much better without 100Hz than I would have anticipated. Sure, there's a touch more judder around than you get with Samsung's B650 range, there's even the occasional appearance of a little motion blur, but neither of these issues is aggressive or commonplace, so the lack of 100Hz seems like a relatively small price to pay for a 40in TV that hits a sub-£550 price level.
Another facet of the 40B550's performance that puts it leagues ahead of the vast majority of the cut-price competition is its contrast. For it manages to produce startlingly convincing black levels within the same frame as really bright peak whites and rich colours. Most budget TVs - and numerous higher-level TVs, come to that - either suffer with extensive grey clouding over dark picture areas, or low brightness levels caused by having to dim their backlight outputs to keep the grey clouding at bay. In comparison, the 40B550 suffers only a little with either issue, allowing its dark scenes to be presented with seriously impressive dynamism and punch.
This picture ‘pop' is further enhanced by the 40B550's colour response. Hues across the spectrum are driven out with vigour, while the screen's Full HD resolution and video processing combine to ensure that colour blends appear free of nasty striping artifacts, and enjoy predominantly natural tones.
You're probably best advised to avoid the Wide Colour Gamut setting if you want this naturalism to remain more consistently intact - but then I have no doubt that some people will prefer the wide colour gamut setting's extra vividness regardless of whether it looks natural or not!