A laptop is definitely not as portable as an iPad. I have taken my 12.9 iPad everywhere with me in the last year. I thought I would give up after the novelty wore out but didn't. It's better in meetings too, others have sketched on it spontaneously. BUT there's a big software problem, nobody has cracked how to do a productive app yet. With Comp and Paper53 being the closer IMO.
I think especially with the MacBook Air and the smaller MacBook that the portability is at least - let's say - comparable. And without an external screen the performance is totally enough for UI design work.
A laptop is definitely not as portable as an iPad. I have taken my 12.9 iPad everywhere with me in the last year. I thought I would give up after the novelty wore out but didn't. It's better in meetings too, others have sketched on it spontaneously. BUT there's a big software problem, nobody has cracked how to do a productive app yet. With Comp and Paper53 being the closer IMO.