So why exactly do you still use a Milestone? Or the Nexus S? Just curious. I'd have sold those things a long time ago while they still had value. It makes upgrading much more affordable.
Once you start actually using these devices, I've noticed that they all lag. My iPhone 4 lagged, my iPad 3 lagged, my Galaxy Nexus lagged, My SGS3 lagged, My Nexus 4 will lag on occasion as well. Still waiting for it to be an actual issue that affects my usage.
What's odd is that every year when the new iPhone comes out you hear people say "It's completely smooth!" but they also say "It's so much smoother than the previous iPhone!" So which is it?
I'm a hoarder of devices. I have sold a few things like the iPad 2 and iPod Touch 1G as iDevices get outdated and that's it. Old devices become tweaking tools. If you noticed the Nexus S gets some weird-ass theme going there.
Well given that the 4S does 60fps no problem, I don't see the 5 as any faster. It may be faster in launching apps, or can handle heavier websites in scrolling, but in terms of basic scrolling performance in the homescreen I don't think we've seen improvement since the 4.
As for webpage scrolling, yeah I've seen it get better over time and I'd say Android needs to step that up still. Just tried Verge now in full desktop and the N4 is fast, but the iPhone is slightly better.