The sweet spot between economy and business. Expect 6–8 inches more legroom, 2–3 inches wider seat, better meal, real cutlery, priority boarding, 2 checked bags and a separate smaller cabin. Fares typically 1.5–2.5× economy — the best value on long-haul daytime flights.
When the upgrade actually makes the flight
Standard economy is 31" pitch. Premium gives you 38–40" — enough to uncross your legs, work with a laptop properly, and actually reach the overhead bin without leaving your seat. Seat width grows from 17" to 19–20".
Multi-course dining on china, welcome drink on boarding, premium wine selection. Virgin Premium, BA World Traveller Plus and Air France Premium Economy menus are genuinely good — closer to old-style business than current cattle-class reheat.
Usually Group 2 boarding, 2 checked bags at 23kg each (versus 1 × 23kg in economy), priority security at some hubs, amenity kit, larger personal screen (13–18"), power socket + USB at seat.
Return fares from UK airports, premium economy cabin
The standard spec across major airlines (details vary)