The positives have been said many times here already. Just don't focus on the few negatives that I will mention!
Setting up a customized shot (field-of-view, exposure compensation, etc.) takes a fair bit longer than on my 35mm because of the time to walk through the menus.
... and, this camera is heavy! That was obvious from the spec's (most people consider a 2 lb 35mm to be a heavy camera), so I knew that going in. That's not even considering the excellent, but also heavy external flash.
I have not yet tried my filter collection, but a lot of filter functions can be accomplished by digital post-processing.
I'm very happy with it after 5 months of good usage.
The manual that comes with the camera is quite easy to use and understand. While the camera does come with lots of bells and whistles, it's not too difficult to understand most of them in a short period of time. I did find it was very easy to take blurry shots with just the slightest movement of the camera during the shot. Use a tripod when its reasonable to use one. If not, HOLD STILL. Use the LCD display only if necessary as it sucks the life out of the batteries. Almost impossible to use it during bright sunlight. Also its too close to the rear eye piece so always expect smudges on it from your face.
The camera is quite heavy but it is constructed very very well. The lense is non-removeable and this has been somewhat of a critcism but I find the lense on this camera is great. I do recommend the U.V. filter and leave it on all the time. A replaced filter is a heck of a lot cheaper than a replaced lense.
As far as service from Olympus. I actually damaged my E-10 (dropped the darn thing) and sent if off to Olympus. (Keep the original box). It was fixed, no charge, and returned to me in 7 days and it works perfectly. That I was impressed with.
In conclusion. Is this a professional camera as touted by others? Naw, not really. But for the money it's a close as you are going to get. Most of the other professional digital cameras are 5k to 30k. With this camera and some practice, you can take pitures that rival a pro. Of course, a good photo printer is necessary. I am an idiot when it comes to photography and the camera takes great shots in spite of me. I do recommend this camera highly.