You must be excited for your trip!! Yay!
You may have/probably already determined which hotel you are booking, but I'll throw my 2 cents in as well.
Two of my favorite hotels at Walt Disney World, both with their attributes that make it difficult to choose or determine which you would prefer.
Boardwalk Inn and Villas Resort benefits:
- Lots of convenient shopping right there on the Boardwalk.
- Pool is relaxing (some people found the clown creepy - clowns don't bother me so it wasn't a factor). What was nice is the pool wasn't crowded. The views of the Boardwalk Villas are relaxing as you lounge by the pool (I say this because you mentioned it is adults only trip, so you don't have children to pay attention to who are swimming).
- The balcony rooms that face Crescent Lake at Boardwalk Inn are AMAZING. Was lucky to get one right above Trattoria Al Forno - beautiful views of the lake, Beach Club, Yacht Club, Swan, Dolphin and Boardwalk. The noise of the busy Boardwalk below did not bother or inconvenience at all. In fact, I don't remember hearing much, unless I was out on the balcony relaxing.
- CloseR to Hollywood Studios than Beach Club is (only by a little), as well as close to Epcot.
Beach Club Hotel and Villas Resort benefits:
- The best pool of any Disney Hotel. Stormalong Bay with it's lazy river and sand bottom is a wonderful experience as well as the pirate ship slide (yes, even for adults) lol. With wonderful views of both the Beach Club and Yacht Club Hotels. It can be crowded if hit at a busy time because of it's popularity.
- I personally found it a bit easier to navigate the Beach Club property than the Boardwalk property, but others may have a different opinion on that.
- Quieter outside atmosphere, due to not having a Boardwalk area.
- CloseR to Epcot than Boardwalk is (only by a little), as well as close to Hollywood Studios.
- Cape May Cafe and Beaches and Creams are nice additions to have right at the hotel.
Equal benefits:
- The theming of both resorts are beautiful. Atlantic City Style Hotel with the pastel yellows and light reds are soothing to the soul. New England Style Hotel with pastel blues and greens are pleasing to the eye and relaxing. (I have a thing for pretty architecture).
- Both have adorable gift shops. (I love shopping lol).
- Both have pretty courtyard areas to sit, relax and view (just outside their respective lobbies).
- It's a great area to go for a nice walk around Crescent Lake - easily walk-able path that brings you around the area with great views of all the resorts. This resort area is (personally) my favorite area of all of Disney World. It just feels serene and memorable to me.
It will come down to probably where you can get a better deal, or what the group preference is. Let us know when you decide!
Both are amazing hotels in their own respect.