tl;dr: the Swan gets a lot right, and if a few things could get tightened up it could be practically perfect. It's a worthwhile option for BonVoy loyalists who want extended Disney hours and are okay with some tradeoffs in exchange.
Disney-related quick hits: If you're prioritizing Epcot and Hollywood Studios, or are cool with inconsistent transportation, then this is a good fit for a Disney trip. Onsite gift shop has plenty of goodies and mouse ears, and you can get Mickey waffles in the onsite coffeeshop (hooray!). There's a lot of talk in reviews about it not "feeling" like Disney, but we didn't feel that way - there are stormtoopers at the elevator, little swans throughout, fountains galore, and generally friendly front-facing staff.
Answering the questions we wished we'd had answers to before booking: rooms are fine and have two sinks, solid AC and beds, and a legit mini fridge. Marriott BonVoy Platinum and above breakfast offering is one $20 voucher per room per day that can be redeemed at Java at the Swan, Fuel at the Dolphin, or towards breakfast at Rosa Mexicano (Dolphin and Reserve offerings are more generous). Yes, you can have food/groceries delivered to Bell Services, but if something requires a signature they won't sign for you. The bus to Disney exists but it is more sporadic than we expected, and drops off in less convenient locations (budget an extra half hour at least, and know that if you stay late in the parks you may have fewer transit options back). You can ask for bottled water (and sometimes ponchos) at the front desk.
Broader thoughts: Like anywhere in Disney, you're going to get a lot of steps in. I picked this hotel over others for the ability to both utilize BonVoy credit and secure extended hours in the parks; on those fronts, it delivers. The challenge is that rather than going all-in on being a Disney property or being a proper Westin, the Swan is halfheartedly trying to thread the needle across both, leading to some weird things and missed opportunities. We were here for a while and over the course of our trip had some things go pretty wrong, and whether they got fixed promptly or at all depended entirely upon who you were interacting with and whether you had the energy to self-advocate. Some folks (especially the phone service night shift) were pretty bad at taking ownership and clearly communicating; others were very very good at what they do. Credit to nightshift security supervisor for his clear communication, and very special shout outs to Monica at the front desk and Zelda in housekeeping.
Room for growth: Swolphin is a big operation and you can tell there are a lot of internal systems and protocols that keep things running, and these aren't always (or often) designed with the guests themselves in mind. Some examples: when we were in the middle of an issue that required a room switch, folks kept saying "we have a protocol" but no one actually explained that protocol for over an hour and the night manager was at the Dolphin and wouldn't walk over; when you pick up the phone and the AI agent understands you want towels it works fine, but when it's midnight and the AI agent doesn't understand "I think housekeeping forgot to replace the shampoo and conditioner because there aren't any bottles in the shower, can I please have some sent up so I can go to bed" and it takes literally 90 minutes to get a resolution, it is less fine; when I ask if I can see the folio to understand how I've used my credit, it would be much clearer to print and hand me the folio vs saying "I can't tell for certain but a little here a little there you're on your way" (huh?). I sometimes got the sense that I was in a hotel on a slightly different planet (which I guess, in some senses, Disney is - but this property also hosts plenty of conventions and as a Marriott, certain things should just be standardized).
Throughout the property but especially in the rooms, the bathrooms could really use a refresh - they've been updated cosmetically but structurally there is only a single hook, the majority of towels are worn and stained and not up to Westin standards, and I have never seen a hotel bathroom more in need of a pocket or barn door (current full door barely misses the toilet when it swings, I kept bumping into it, and it and has significant water damage on the bottom and the edges - probably largely because the shower curtain is bizarrely short and as hard as I tried, I couldn't avoid partially flooding the area outside any time I showered). Modern step-in showers with glass doors and towel racks would do a world of good here and prevent both water damage and safety risks for guests.
Suggestions for the Swan are the same as anywhere I stay, but a little more punctuated given the high hopes and significant investment of time and money people are making when they come to Disney: I'd recommend hiring a secret shopper who frequently travels for a few nights and getting their honest feedback, ordering some new towels, reinforcing with staff that clear proactive communication in guest interactions goes a long long way, and please for the love of Mickey add some hooks to the hallways and bathrooms.
