What’s the best way to choose between uPVC and aluminium windows for a home in Suffolk’s climate?

I’m in the middle of trying to sort out new windows for my little place here in Suffolk, and honestly my brain’s doing somersaults. Half the folks I talk to swear by uPVC, the other half rave about aluminium, and I’m stuck in the middle just wanting something that won’t leak, warp, or make my heating bill cry. The weather here is all over the shop—windy, damp, salty air from the coast—so I’m nervous about picking wrong. If anyone’s been through this or has some real‑world wisdom, I’d love to hear it. I’m all ears!