I got into M4/3 two years ago with an E-P1 and a Panny 20/1.7, and expanded with MF glass and CCTV glass. I really enjoyed the form-factor of the E-P1, but I did not like it's files above iso 800, and the live view only composition method grew tiresome.
Sold the E-P1 last year, and moved into a new Panasonic G3, mainly for the EVF. I did not think I'd use the swivel touchscreen, but to my surprise those two features are quite useful and get used a lot. Great files too, from the second gen sensor, and useful files all the way up to it's iso 6400 limit.
What I do not like about the G3 is the lame auto iso setting, 200 to 800 only? Come on! An extremely useless Cfn button and a few other nit picks.
Several months ago I bought a refurbed E-PL1, it was cheap and I wanted to see how the weaker AA filter would affect the files. Great camera! I love it and it's output. Yeah, consumer grade access to camera functions, but I can live with that.
Well, I've been saving up to get me an OM-D, it'll be nice to get back to enthusiast controls and an enthusiast body for a platform I truly enjoy. I've considered the E-PL5, but my god that body is small. Also, add a V-F2 and now the E-PL5 costs nearly the same as an OM-D.
M4/3 has been an enjoyable ride so far, and I feel Olympus has the upper hand in the M4/3 photography department over Panasonic.