I can't think of a time I've been to a Starbucks Reserve location and felt that the difference amounted to more than slightly bougier interior decorating. Same as any other Starbucks otherwise, and generally the coffee isn't better
Their roastery in Seattle is quite different though and worth visiting since they do have good coffee, interesting merch, interesting architecture, etc.
I mean, that's also a roastery, not just a "reserve" location, and that's the New York location which might as well be the Times Square Apple Store compared to some small town Apple Store.
Other reserve locations, such as this one in Tokyo https://maps.app.goo.gl/diFWHoByG3783V8u5 or this one in Vancouver https://maps.app.goo.gl/HGWsXsinAparQ7bGA are pretty much "slightly bougier" locations that as far as I know don't really have anything unique going on, with the exception that you can sometimes get shitty coffee made in a siphon brewer.
The roasteries always seem to get that special touch though.