--Thank you for posting this photo of the insides of the plastic with metal clad skin E-P1 which I hope others will view to see that is the real arguement of metal vrs plastic with these cameras.
If you were to look at a similar picture of the all metal GF1 you would see that the most critical center part housing the lens mount, sensor, shutter, etc holding them in precise alignment are all milled from a single solid block of stainless steel as illustrated in a PP picture of insides and attached as the body panels to a metal frame.
I don't know why DPR continues to claim in the specs that E-P1 and E-P2 have metal bodies as the picture very clearly shows this is not the case. While the outer plastic shells can be made just as tough as a metal one as more prosumer DSLRs are now using in place of magnesium bodies to reduce cost & time to produce that is not the same as the interior body where EPs using construction similar to that used on most cheaper P&S compacts. Because everything is very compact inside with such a small body and the generally small lens designed for same this is just fine for most people, but I wouldn't personally expect such camera to last anywhere as long or handle larger lenses as my old reliable SLR FM or OM bodies or my DSLR K10 or Kx with metal frames for the matter.
Having an all metal body will become more and more important as people try using these cameras for HD video. Plastic does not conduct heat well from the sensor so must be shut down after only short periods of operation say 7 minutes on most to avoid overheating while no limit with metal body? The GH1 does go longer but that is with a larger body with more air space inside less compacted than the minis and smaller m4/3 sensor compared to APS-C.
I think many camera manufactures are building these camera bodies as cheaply and as fast as they can as a result designed to wear out quicker construction and frankly looking at some of the entry DSLRs out there I am frightened by what appears to me to be very flimsy shells indeed for the very fine mechanical and optical camera components put inside? Just my opinion but in my haste and working in adverse environments I am harder on my equipment than most.
I have accidentally dropped both my FM SLR as well as my tough K10 DSLR accidentally to concrete without damage to them or their metal housed lenses. On the other hand I have had a plastic zoom lens tumble just a few feet to heavy carpet and find the AF made inoperable from the fall!
I also question the adviseability of screwing metal machined screws to attach and hold the lens mount and heavy lens into a plastic thread plastic block?
Plastic may be lighter but then magnesium is not very heavy and the GF1 body is lighter than that on any PEN but probably much of that is due to the IBIS mechanism found in the latter.
Even if the EPs and GFs had equal AF speeds I would probably chose the latter simply because of my preference for its metal body build and the hard use I would subject it to in carrying it with me most of the time. With the 20/1.7 I don't need IS and with Panys zooms I have OIS anyway so IBIS less of a factor even though I wouldn't have a DSRL without it as have in both my 5D and K10 so I probably take its advantages just a bit too much foregranted.
