Paul, I agree...
It's a shame that the original poster on that subject/thread is a bit too sensitive to the discussion of a drum room or drum sounds to not see past the fact that while I (and others) express their opinion about my/their facility, that no two folks in this industry are going to want or need the exact same thing... as it would have been really nice to help in seeing him develop a studio plan and execute it.
Virtually everyone in the industry agrees that the days of the new large studio complex being essential, are over. That means that it's the small studios are all that are essentially producing the majority of the music out there... and will continue that way for a long time to come.
To the point of economics... IMHO, there are actually two main philosophies of the new breed/generation of studios and studio builders/owners; "Build it and they will come." and "This place ain't big/good enough enough for the amount of work I have."
If you're in the former mindset, you see studios being built (like mine) that are based upon the reality that the studio will most likely NEVER pay for itself, and you see more attention being spent on things such as purpose built rooms and the aesthetics/creature comforts.
In the latter philosophy, there are tighter constraints on the economics involved, as the facility MUST pay for itself as quickly as possible.
Neither philosophy is right, neither one is wrong as they both meet the needs of the investor.
It's my humble opinion that latter group is at a disadvantage, but only financially. There may be some aspect of a studio that they wish they could have, but cannot justify investing in. This is why it's so terribly important to get the best bang for their bucks as possible, by trimming whatever fat they can from the build, and/or using their space as efficiently as possible.
Efficient usage of space and a well thought out plan directly tie in with your point about good sound.
AFAIK, a "bad sounding room" is not usually a goal except in the Foley world, so lets "assume" that a given studio has "good" room(s). If you deliver to the clients what you want, and what the client wants... then you've done good... regardless of what the room actually sounds like.
Which leads to the personal enjoyment of working in a studio... if the clients are happy... then the studio personnel should be happy.
To the point of the overall direction that the other thread took...
Anyone taking on the task of planning and building a studio must first realize that physics are involved, and you cannot defy certain things in the physical world such as highways with heavy commercial traffic, airports, railways and the like.
See Rod's sticky: READ THIS BEFORE YOU POST [/edit]
If you record music in location(s) where these things come into play, (and I do have those to contend with when I'm on a remote location recording), you either have to live with them or you will need to address how to eliminate/minimize their effects/influence.
After that, it's up to the investor to determine a budget, find a location that suits their needs within that budget and THEN develop a strategy that fits their needs within that budget.
It's that simple...