Verdict. Buy one, learn to sharpen it, and skip the block set entirely. Sharpness matters far more than price above about the £40 mark.

Knife discussion collapses into steel metallurgy very quickly, and almost none of it matters compared to one variable: is the edge sharp today. A £30 knife sharpened last week cuts better than a £300 knife sharpened last year, and it is safer, because a dull blade needs force and force is what makes it slip.

Choosing one

Length: 20 cm for most people. 15 cm feels safe and runs out of blade on a cabbage; 25 cm is unwieldy on a small board.
Hold it before buying if you possibly can. Handle shape and balance decide whether you enjoy using it, and no specification captures that.
German vs Japanese is a real trade, not marketing. Softer German steel is tougher and forgiving, holds an edge less long, and sharpens easily. Harder Japanese steel takes a finer edge and holds it far longer, and chips if you treat it carelessly.
Full tang, no bolster over the heel. A bolster running to the edge stops you sharpening the last centimetre and makes the knife hard to rock.

The maintenance that actually matters

Honing realigns an edge that has rolled over — a steel or ceramic rod, ten seconds, once a week. It is not sharpening and it removes no metal.

Sharpening removes metal to form a new edge. A whetstone is the cheapest and best option, and it is a genuinely learnable skill in an afternoon. Pull- through carbide sharpeners work and take years off the knife; use them only if the alternative is never sharpening at all.

Never the dishwasher. Heat, detergent and knocking against other items: all three are bad, and the handle usually fails before the blade.

What else you need

A paring knife for small work and a serrated bread knife, which cannot be sharpened conveniently and is therefore the one to buy cheaply and replace. A board that is wood or plastic — glass and stone boards destroy an edge in a few strokes. That is the complete list.