I think it depends on your personal wants and needs, The mugs do make an inexpensive souvenier.
We don't drink enough soda to make them worthwhile, regardless of the type of accomodation we are staying in, and I think that's something you need to consider.
Generally speaking most concierge lounges are open from early morning until later evening. And even outside of "normal" daytime lounge hours, you can generally get beverages.
Anne