PTFE nonstick vs bare or anodised aluminium

Which one heats faster?

Neither spreads heat faster. The aluminium body of PTFE nonstick and bare aluminium both conduct at about 237 W/m-K, so the difference between them lies elsewhere. Conductivity is how quickly heat moves through the metal, and at these figures the two spread a burner's heat in much the same way. Responsiveness to a change of heat depends more on thickness and mass, and there both rate very high.

Conductivity is not the same as heat retention, and confusing the two is the most common misunderstanding about cookware. Cast iron conducts poorly at about 52 W/m-K and retains heat extremely well, because retention comes from mass and specific heat rather than from conductivity. That is precisely why iron sears well: the pan barely drops in temperature when cold food lands on it.

Which one suits which job?

PTFE nonstick is best for eggs, pancakes, delicate fish, and anything that would weld itself to bare metal. A nonstick pan is a consumable, not an heirloom. Coatings wear out with normal use, and a worn one should be replaced rather than scrubbed harder.

Bare or anodised aluminium is best for sheet pans, cake tins and commercial bakeware, where even heat and low cost matter and induction does not. Aluminium conducts about fifteen times better than stainless, which is why almost every good stainless pan has aluminium hidden inside it.

Practical differences that decide it

Induction: PTFE nonstick works on induction only with a magnetic base and bare or anodised aluminium does not work on induction. That alone settles the question for anyone with an induction hob.

Acid: Bare or anodised aluminium is reactive, meaning long acidic cooking strips seasoning or discolours the surface, so tomato and wine braises belong in PTFE nonstick. Oven ceiling: 400F against 500F, remembering that the handle usually decides the real limit rather than the material.

Weight and upkeep: both are light. Neither requires seasoning.

The honest conclusion

Most kitchens should own both rather than choosing. They are good at different things, and neither is a substitute for the other. A mixed kitchen outperforms a matched one at every budget, which is the single most useful thing to understand about buying cookware.

If you genuinely have to pick one, pick on the job you do most often. For searing and browning, neither is a real searing pan. For sauces and anything that needs quick control, the two spread heat at much the same rate, so choose on responsiveness and upkeep instead.