Sorry so slow on the reply - I just hate it when work gets in the way of thinking about Disney!
Anyway, yes, when we got there I just told the first bellman we saw that we were staying concierge. They then took me to the bellstand where they called and got our room number (it was already ready and it was only about 10:45 am). Then we plus all our luggage were transported via big golf cart to Hawaii where we were taken straight back to the room. After a few minutes, I went back out to the Hawaii CMs and did the official check-in and got keys, all important papers, etc. Very easy and very quick, except the nice CM telling me all about the dining plan, park hours, etc. I could have cut her off but just didn't want to.
The Hawaii CMs were always very nice and accomodating. They're always there, except past I think 10:00 at night. Not sure when they arrive in the morning, but I believe it is no later than 7:00.
The walk to the GCH is nothing - very short. To the TTC is a good bit longer, but is very pleasant. The only time it seemed too long was after a late night at Epcot, but I think it had more to do with the food and wine than the walk.