If you are into architectural or landscape photography you will love this tiny lens.
It’s really sharp at every aperture, just a tiny bit foggy at full speed (typical of designs without aspherical elements).
The contrast is nowere in the range of the Contax lenses, but this in my book it is a blessing because it means no easily lost highlights.
The colors are simply gorgeous, warm and, for lack of a better word, “vibrant”.
The raison d’être for a shift lens like this one, not too wide indeed, nowadays is mostly rooted in the fact that it will let you shoot two or four frames to stitch together to gain resolution with extreme ease.
For this kind of work this lens is as good as it gets, because unlike other brands Olympus made the shift procedure silky smooth: you don’t have to move switches, just push or pull the lens in the right direction and it will slide in position (and stay there).
It is so well implemented that you can do this even handheld! And given how small it is, smaller than some other “normal” 35mm (i.e. without shifting function), you really have no excuse not to carry it with you as a general purpose lens.
Besides, shifting the lens will let you change perspective (for example you will be able to shoot from below without having to crouch down), cut unwanted elements from a scene and, obviously, even correct perspective in an architectural shot.
This little lens has only two potential flaws: first of all it is not so resistant to flare, especially at full speed; and in some copies the slide movement with the time tends to loosen a bit, but this is easily fixable. It’s just a question of tightening up a couple of screws that are accessible after sliding the lens.
In conclusion: my advice is to get one, they tend to be around 300 / 350 € on the auction sites, in good shape. The next big thing is the Contax 35mm shift, that is better but it costs three or four times more!
Rating: 
I agree with your comments. I have had one of these lenses for more than 30 years. It has been my most used lens, largely for eliminating foreground distractions (such as inconveniently located obstructions) simply by moving my location by a few feet.