Who is disappointed with the Oly 45mm lens?

Olympus had excellent QC with 4/3, but that seems to have disappeared (maybe one of Mr Woodford's reforms?) with m4/3.  If your lens is bad, send it in for repair.  Olympus frequently just gives you a new lens at repair price, rather than fixing your actual lens.

You have three possibilities here (or a combination of the three):

1.  You have bad lens.  Test it properly to find out.  It should be sharp across the frame, colorful and contrasty, but not look the same as Panasonic because they have different rendering characteristics.  Make sure you are not confusing sharpness with contrast, as those two properties get confused often.  If it is bad, get it repaired.

2.  Your technique is bad, especially if you are already predisposed to think the lens is disappointing.  See above.

3. You are disappointed that the Olympus lens doesn't look like a Panasonic lens.  I have used both companies' lenses since regular 4/3 and they do not produce the same lenses.  Their priorities are different and the lenses are different.  I don't think one is 'bad' and the other 'good', they are just different and serve different needs.

As a broad generalization (and there are many lenses that do not fit this but it works for me as a way to think of the two brands), Panasonic lenses are bigger, heavier, more expensive, have more 'flaws' such as CA (fixed in Panny cameras) and vignetting, and have beautiful, contrasty rendering which makes you forget about the 'flaws'.  Olympus lenses (another broad generalization which doesn't fit all lenses) are smaller, lighter, less expensive, have fewer 'flaws' and rendering that some consider to be 'clinical' and some consider to be 'optical precision', which I personally consider to be 'neutral'.  Olympus has the absence of a rendering 'look', which is highly useful for some types of work, while Panasonic has a definite and beautiful rendering 'look', also highly useful for some types of work.  There are also performance differences between the two brands of lenses, at least on Olympus cameras (no one has ever answered whether they behave differently on Panasonic cameras).

E.g., I have both Oly 45 and Panny 45.  I bought the Panny 45 (used) for macro shooting, but I don't like it for that because it is too contrasty for my tastes for macro photos.  It is beautiful for portraits, but I do miss the faster aperture of the Oly for portrait work.  It is sharp and contrasty for 'moody' landscapes and city scenes, although I again miss the faster aperture for low light work.  Truthfully, the Olympus is more versatile and a terrific lens in its own right, and now that there is another option for macro work, I would not buy the Panny.  But it does have very beautiful rending, so I haven't yet sold it.  I'm trying to find uses for it instead.

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Roberto M.