Hi Andrea,
Tom and I took our first Regent cruise on the Mariner this past June/July in Alaska and we had a butler suite, too!
Raul was our butler and he was great! We never asked him to unpack or anything like that just the normal "stuff" you'd ask of your room attendant. The one thing we did ask him to arrange for us was a galley tour and that was a lot of fun.
Our favorite place to sit and watch the world go by was right in our suite either on the balcony or with the glass doors wide open sitting on our sofa.
Another spot we loved was the Observation Lounge with a "front row" seat and a lovely glass of champagne.
Actually anywhere on the Mariner is simply wonderful!
You will have a wonderful time!