You get some features that work great with you camera like wireless and AF assist if you get the FL-36r. Im not sure if the output is up to par with metz but you will not regret going with Olympus.
Here is a article about it. (about the fl-36 non R)
The FL-36 and its big brother, FL-50 from Olympus, are the only two flash units on the market supporting a full TTL automation with the Four Thirds E-System cameras on one hand, and offering a bounce/tilt capability on the other. Some flashes from other makers (in particular, Metz and Promaster) come close, but not all the way.
Before I go info details on the FL-36, let me briefly list the alternatives from Olympus:
The older FL-40 does not provide the TTL (through the lens) coupling with the E-300 and E-500 internals: you can use it only in the "Auto" mode, with the camera set to manual and the flash itself determining the light output. (The exposure accuracy is still good, though.)
I am surprised why; the FL-40 should be capable of full TTL automation, except for the high-speed synch, and it works in TTL auto with the E-1! Omitting the support for that flash in the E-300 and E-500 is a questionable decision by Olympus.
The tiny, simple FL-20 integrates well with E-System cameras, but it provides much less of a light output and, obviously, does not tilt or bounce.
The FL-50 offers very good specs, but it sells at $400 or so — not quite your lunch money. Therefore the FL-36, at $200 seems to provide just the right combination of performance and price for most of the E-series users.