Mac4ever compares the iPhone 17 Pro, now around €1,200, with the iPhone 18 Pro at €1,479 — over €300 apart. The verdict is clear: same screen (6.3″ OLED, 120 Hz, 3,000 nits), same design, near-identical battery life (31 vs 34 hours), and an A19 Pro chip that's 'more than powerful enough' next to the A20 Pro and its +40% graphics gain. The only real differences are in photography (variable ƒ/1.48–4.0 aperture on the 18 Pro). The article's conclusion: apart from pro photographers and demanding gamers, everyone is better off taking the 17 Pro and keeping the €300.
For apps, that comparison says something important: the newest model's raw power is almost never what makes a good experience. Most people keep their iPhone three, four, five years — so your app runs mainly on chips from two or three generations ago, not on this month's flagship. At Devside, we design and test for that real installed base: smoothness on a mid-range device, fast launch, controlled memory and battery use. An app that flies on the latest iPhone but stutters on the one people actually have in their pocket is an app that disappoints the majority. The right instinct isn't to target the newest device, but the most common one.