OSX UI smoothness differences between 13" and 15"

So, can anyone tell me if there is a noticable difference in UI smoothness between the new 13" and 15" rMBP? Mission Control, switching between spaces or fullscreen apps, resizing stuff, etc. I'm only interested in the "best for retina" setting on both devices, as I know things can get laggy on the 13" in scaled modes.

Basically I'm wondering if Iris 5200 has smoother framerates in OSX animations than Iris 5100 in default display mode.

 

That's great to hear!

I'm about to buy a new rMBP and UI smoothness is a big deal for me. I've used a 2013 13" MBA and the UI was always performing smooth on that machine. Benchmarks show the 13" MBA and the 13" rMBP are pretty close to one another in terms of performance, so I was in doubt wether the 13" would be able to offer smooth UI framerates having that much more pixels to render.

I would have seriously considered the base 15" model just for UI smoothness alone. But if the 13" is smooth aswell, then I'd rather go with that one for increased portability. Won't be needing the processing power that much

Thanks.