I have played with a Lensbaby at a camera shop a few years ago. They were kind enough to load it up to let me try and I was quite pleased but not sold on such a device. Tilt Shift is great for diorama photograpphy, which is used to shoot toy or model sets to give it an added dimension of reality. It is not used in architectural photography. For that you need a "shift" lens, and not a tilt one.
Now I am not knock the lens. It has its functions and coupled with other lenses, the Composer still has quite a few tricks up its sleeve. None however, which you cannot already duplicate on photohop or a image editing program on the iPad or iPhone. Lens Baby even went on to amateur photogs to endorse the effect, saying it's better than the digital variety found on apps. But take it from me. It is not.
And therein lies the problem. In film photography, where the final image is recorded on film, the Lens baby would be a superb tool. But for digital photoraphy, it is at best, a toy lens which you can buy to indulge your senses.
Would I buy it? Sure I would, I still own film cameras with a Nikon mount. It would be a nice addition to my analogue lens collection too. But I wouldn't waste my time with it on a digital camera regardless of what those "pros" have to say. What's more, people use the Composer in a more casual manner, thus there is no reason to buy the lens if you were shooting professionally. Here lies the other problem. If you don't or can't use the lens professionally, what's the use of spending that much on a lens?
The average man on the street is not going to be able to tell if you used a tilt-shift lens or a tilt-shift app on a digital image. Who the hell cares anyway as long as the creamy bokeh looks good enough to eat? I wouldn't and that's for sure.