If you are into the architectural or the landscape photography you will love this tiny lens.
It’s really sharp at every aperture, just a bit foggy at full speed.
The contrast is nowere in the range of the Contax lenses, but this may be a blessing to avoid lost highlights.
The main purpose for a shift lens like this one, not too wide indeed, is to stitch two or four frames together to gain resolution.
For this use 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.
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 tend to loosen a bit, but this is easily fixable. It’s just a question of tightening up a couple of screws that are accessibles 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.