Sadly, the quality doesn't show through. I could take a picture of the 11x14 over my computer, but you can't tell that there's absolutely no grain, or that the progression of greys from jet-black to straight-up-white (Zone 1 to Zone 10, if you're into that) is perfectly smooth.
Like the poster you show -- it's nice, for sure, but from here the relections and lighting problems nullify much of the quality.
Did you shoot that? That would have been really incredible. What kind of film did you use? Can you see the grain at that size?
Suffice it to say that 4x5 is like MF, except more so.
Not so convenient as the smaller formats (in fact, quite a hassle sometimes), more expensive, but having big negatives is sometimes worth it.
Having shot with a number of different MF cameras, I'd be curious as to your opinions -- some of the folks say that a Hassy is absolutely the finest. Others say that it just isn't worth the money, and you'll do just as well with a Mamiya/Rollei/etc. My dad's line: "Sure, the guy with the Hasselblad gets some good pictures... but I'm always amazed at the work that the 8 year old does with a little Brownie Box!"
Dan