It sounds like you'd benefit from spending some time with a traditional view camera. Such a camera would let you more fully understand what all this "Tilt-Shift" is all about. Many digital shooters who've never used a 4x5 struggle with using t-s lenses. I use all three of the Nikon PCE's with my D800E and find each useful in their own way. Classic architecture may be best served by the wider lenses, eg the 24mm. It is arguably the most difficult to use well though, perhaps because small movements can do a lot. I knpw nothing of the Samyang, Hartblei, Schneider or others for modern digital cameras but it sounds like you need education before you get any lens. I mean no offense or insult when I say this. It's better o understand the basic principles, and I don't mean complex equations or physicis. It can be as simple as "focus on the far, tilt toward the near, tilt and refocus until all is clear."
