IMHO Rivendell owners are not very objective. They are fans of an ethos and sometimes their opinion of the bikes needs to be taken with a "pinch of salt". I own 3 Rivs. I like the Ram and the Quickbeam, but I'm not a fan of the Atlantis....it's a bit sluggish and I might sell it. So you'll get a nice bike if you buy a RIvendell, but there are plenty of cheaper places to buy a bike that you'll probably like just as much.
Agree. There was an excellent thread on this maybe 7 or 8 years ago where Bekologist had me laughing my arse off. When I lived in CA, some of the Riv owners I met were outright cultish. I used to be a Riv Reader subscriber and I can see why: Grant sells - as you say - an ethos, and he hits the sweet spot for people (I am one of them, but not a Riv fan in particular) who miss certain old-fashioned things like classic aesthetics and love of both hand-crafting and the many "retro" designs that didn't need to disappear, weren't necessarily inferior, and yet were replaced by the sci-fi bew bew plastic CAD-designed engineering we see today. (I despise your Cervelo Star Trek bicycle in the looks department, for instance, no offence.)
I like Riv bikes okay. Smart designs for the purpose and I can't think of too many better things to say about a bike frame than that, but they are a definite boutique product and I don't consider them super special. How much the frame design is important compared to graphics/curly lugs and GP idolatry for various Riv fans I can't say, but oh boy, some of those I've met...oof. They remind me of Harley riders.
I'd much rather have a custom for the money - seeing as how a custom is you telling a frame-maker exactly what you want, up to and including copying any particular features of any Riv frame like oversized head tube, cranked out stays, etc. Even a semi-custom like a Waterford* I'd take over a Riv pre-built.
If I were in the market for another frame and was fine with a non-custom (I'm not; my custom is nearly perfect for me because it was mostly designed by me), I'd be checking out Hillary Stone's site and eBay too. There are used frames from the UK in particular that are just lovely, many of them totally meant for touring of various types, complete with the fancy lugs and old world graphics, etc, and they are way cheaper than buying a Riv off the peg. This route takes patience though, and ideally with some of the 1950s-70s bikes one might want to do a restoration project, which adds to price.
*Edit: Or not! Holy moly, Waterfords went up in price quite a bit since last I checked.