You could probably ask this over at DPR, but I have the EP1 and am trying the NEX5. Sweep panorama is more useful to me than art filters, and the sweep pano really does work, and AF on the EP1 kit lens is slower than the NEX5, but it's the fault of the kit lens (which collapses much smaller than the NEX!). If you use the 20mm 1.7 or the 14-150, they keep up with the NEX in my experience.
I have a few lake pictures and such posted on here built using that, it's easy to use and it's pretty good merging quality. The resolution of the panoramas is better than the ones I've seen pulled out of the sony's mainly because sony scales down the images significantly (at least on the cameras I played with) where as the software will merge the full resolution images if you want.
Most of the art filters are also available in post-processing applications and do just as good if not a better job than in-camera ones too.
If you're trying to decide what to buy, my personal advice, is to focus on the camera itself and use just your computer to do the after effects.
The gimmics can be quite attractive but should never be the main reason for choosing a camera. Look at all the other features and characteristics, especially handling, and if your eventual choice has some nice gimmics then that's just a bonus. :smile: