It really depends on the concierge. When we sailed in the GV, we had 8 guests in the GV, 5 guests in a 2-bedroom suite, and 4 guests in an inside cabin. Our concierge set-up dinner for the 17 of us to have at Teppanyaki. He comp'd the cover for the 8 guests staying in the GV and the costs of sodas/juices for all 17 guests. That was our dinner instead of with the hotel manager or other officers, which was fine. We had a great time having both grills for our entire group.
Our concierge also gave us a tour of the bridge. We weren't sure if his invitation was for the 8 guests staying in the GV or all 17 guests, so only the 8 guests that wanted to go the most went. When we meet the concierge, he said that his invitation was for the entire group but it was too late by then.
Because our group was split between Haven and non-Haven cabins, we were reminded the first day that the non-Haven guests could not use the Haven Courtyard area or have meals in Cagneys/Moderno, which we knew going in. (The guests in the inside cabin where my brother's single guy friends who booked the cruise at the last minute.) The concierge did allow the four guys in the inside cabin to disembark in ports with us. He certainly wasn't required to do that, but we appreciated that he did. I think it helped that the bulk of our group were staying in the Haven.
(Side note, security did get to know the guys about half way thru the cruise. Another guy on the ship wanted to start a fight with one of them, but they all walked away instead of throwing a punch back. Security camera footage and crew-member interviews confirmed that none of the guys provoked or fought back, which they said was one of the first times they've ever seen that. Either the head of security or the captain later came up to the GV with the concierge to commend the guys on how well they handled the situation. They seemed really surprised at how it ended up being only one-sided. Typically, both people will be kicked off the ship.)
As for the butler, I can't remember his name, but we really liked him. He was personable and shared stories from other cruises with us. He also seemed to appreciate that we were a very laid back group and not what he was typically use to in the GV. He was anticipating another rough week after us. It was either the size of the group (very small) and/or known prior guests. I got the impression that he much enjoys larger groups to smaller groups. And I get it. A big group pooling resources to do something so amazing and otherwise inaccessible is going to have an entirely different dynamic.
That cruise was in 2014, and we haven't been able to figure out a way to make it work again since then. Certainly have tried, but with the pricing increases and the free-for-all packages, it just hasn't worked out. A year ago, we began planning an Alaskian cruise on the NCL Jewel for 2020. Booked two 2-bedroom Haven suites for 8 guests, hoping that we could upgrade one to the GV with the bid process. Well, when the 20% latitudes sale was announced, we re-evaluated everything and decided to do a GV instead of the two 2-bedrooms! Also pushed the cruise back two weeks so that we're starbooard on the Northbound route. Already planning on having breakfast and lunch brought into the cabin on the day we're in Glacier Bay National Park! Should be incredible being able to be in the hot tub as we watch glaciers go by.
(In case you're wondering about the 7th & 8th guests, there is a couch in the master bedroom that flips 180-degrees into a twin bed. There is also a chair that folds out into a twin bedroom in the third bedroom. So 8 guests doesn't work well when it's all adult couples.)
One thing to get use to is that staff will be in and out of the common areas of the GV frequently, such as the concierge checking on your there. But, only the room steward will go into the bedroom areas. Even had a bunch of officers storm the GV one afternoon because the steam room set off the fire alarm.
So, bottom line, enjoy it! Try not to have expectations about what the butler/concierge will offer/do because it can vary SOOOO much. It'll be an incredible experience regardless!