Traded my D90 to an EP-3 and now starting to ask why I did it.

In what way do you find that it isn't better or at least close?

I would ask yourself this... Does the EP-3 produce adequate image quality for the print sizes that you make? There is a big difference between pixel peeping and real world results when laid out on paper. The D90 may be able to be printed larger than an EP-3, but does this exceed the size you print?

I would bet that if you don't print any bigger than 11x14, you won't see any difference in print. If that's the case, buy lenses and enjoy it. Then later on buy one of the newer bodies like an OMD or GH3 that are better than what your D90 was and use the EP-3 for a 2nd camera.

About the only place I would see a D90 being significantly better than an EP-3 is at ISO 1600 & 3200. But with that said, I think the best street work has some grit anyway. It tends to add character and texture. Most of the best old street shooters were Tri-X people.