I had my first experience of T4 on Tuesday this week as an arrival on CX.
The absence of travelators was particularly noticeable and the couple that are there on the very long walk from the plane don't make any sense at all but were welcome.
There was no wait whatever at immigration, I was first off the plane but clearly there was no other activity at the time either and the place was deserted though about 10 desks were staffed.
Luggage delivery took rather longer than I would have liked given that there clearly was nothing else happening. In T1 I was used to my bag being on the carousel when I got there with quite a lot of other activity too. It took about 10 minutes after I got there for bags to begin to arrive and mine - with priority tag was in the first 10.
Making my way outside there were only two taxis waiting as opposed to the never ending availability at other terminals - glad I was quick and no doubt more came along but having to wait is always time wasting.
I guess I'll get a further impression when I fly out from T4 as arrival and departure are often quite different experiences but this time I'm leaving from T3.