So, if it's so perfect, why do I have other cameras? Well, there are times when even the smallness and lightness of the OM's is beaten by the pocketability of smaller cameras, albeit with the compromises that using other cameras entails, such as ultimate control and the ability to use interchangeable lenses. Also, an OM isn't as discrete as, say, a Mju-II or a Trip. Or XA. People don't notice small cameras, but they do see an SLR. And, again, if push comes to shove, the resolution of my Summaron on my M2 is greater than the Zuikos on the OM's. No surprise there, given the design restraints on interchangeable lenses and the need for there to be space behind the lens for a flipping mirror.
A note about the Zuiko lenses... Well, my experience of them that is. To be honest I'm not as gung-ho or effusive as many devotees appear to be. Now, of course, there is the age factor creeping in and some performance may have dropped off as tiny imperfections may have accumulated, and I also believe there is some sample variation, possibly from new or from ageing issues. In any case my stand out superb Zuiko lenses are an f2.8 24mm, both f1.8 50mm standards I have, and an f3.5 135mm telephoto. These three form my clutch of lenses when I go out. I also have an f2.8 28mm and an f2.8 35mm which are really, it seems, not up to much unless you're able to operate around f5.6. They're ok, of course; photos get taken and everything works, but an image is just not as resolved as it might be. My first second lens was a Vivitar f2.8 28mm lens and this was as good if not better than the comparable Zuiko I bought more recently. It wasn't a Series 1 or anything; just their standard OM-fit offering. If anyone isn't hung up on the Zuiko name and want a 28mm - go for it, you won't be losing anything, and for all I know this holds true to any other focal length
Here are some more because I can.