I figured I'd write up a brief analysis of my initial thoughts of an E-M1 I just purchased, as it may be of interest to other Panasonic users who are looking at Olympus cameras. Some items will be E-M1 specific (ergonomics, button placement, etc.), but others are universal to Olympus (menu layout, IBIS, etc.). I'll start by giving a bit of background. I currently own two GH4 bodies and a host of native m43 lenses, all of which are Panasonic branded. I enjoy shooting motorsports, as it combines two of my favorite hobbies (racing, and cameras), but was frustrated with the performance of the Panasonic 100-300 in this regard. My main gripe with the lens was that it used an older aperture mechanism that limited the burst rate that's achievable when shooting in C-AF mode at anything other than max aperture. My 35-100 f/2.8 can easily achieve the 7fps that the GH4 is capable of delivering in the "medium" burst mode, yet the 100-300 would only achieve around 2-3fps. So I sold the lens, and figured I'd give manual focusing a try with zone focusing. I bought a 4/3's Olympus 50-200 (non-SWD) at the end of last season and got to use it once, where it performed pretty well. Still, I wanted to have the ability to autofocus the lens when needed, and the only camera that could do so was the E-M1. I had been keeping my eye on used E-M1 prices, as they had been falling and were hovering around the $700 mark. However, I was alerted to Olympus' 25% off sale, which brought the price of an E-M1 down to $540. I jumped on it, figuring that if I didn't like the camera I could always return it or sell it for a marginal loss, far less than what it would cost me to rent an E-M1 for even a few days. I received my camera yesterday, opened it up and much to my surprise, it literally looked like a brand-new camera. I checked the FW, which was still on 3.0, and I found this a bit odd because I figured that all refurbished cameras, as part of Olympus' "check", would have the FW updated to the most recent version. So I set about updating the FW to 4.1, which was way more hassle than it should have been (I have a whole thread about it, but the issue was that I had my sleep timer on the camera set to 1 minute, which prevented the FW from installing. A silly little issue that I never would have thought of). After updating the FW, I took some test shots and set the camera up to my liking, and then decided to check the shutter count. Much to my surprise, it only had a handful of shutter activations, and even fewer power-on cycles. I'm not certain if Olympus resets this info for refurbished cameras, or if I honestly got what appears to be a brand new camera. Either way, so far, so good (with the exception of the firmware update). So, what do I like about the camera: The EVF is very nice. It's bigger than the one in my GH4, which I found more than adequate. I plan on getting the larger eye-cup though, as the one that comes on the camera is quite small. IBIS is very nice. I put it through a "real world" test using my 12-35 f/2.8 with OIS off, and saw 3 stops worth of stabilization. If I really focus on being still I could eek another stop out of it. The size. My god, do people really complain that the E-M1 is "large"? Coming from two GH4's (which aren't really that big in the grand scheme of things), the E-M1 is noticeably smaller in the hands. The button placement is very nice. I particularly like the two buttons on the left hand side of the top plate by the On/Off switch that allow you to select metering, drive mode, etc. The menus. The menus are not as intuitive as the Panasonic menus, but I feel that they get blown completely out of proportion. It took me 15-20 minutes to go through the menus and get the camera set up to my liking. The "info" button is a very handy tool to use when going through the menu, as Olympus' naming structure is a bit confusing, but the info box clearly explains what each item does. What I don't like about the camera: The size. I put the size as an advantage, which it certainly is, but it's also a slight disadvantage as well. I have rather normal size hands (for anyone who's ever worn latex/nitrile goves, I wear a size M), and my pinky completely hangs off the bottom of the grip. This is fine when using the camera with small prime lenses (which I'll be doing thanks to IBIS), but for using it with bigger lenses (like the 50-200), it needs something more. I plan to order the RRS bottom plate, which adds about a half inch of height to camera and would give my pinky a place to comfortably sit. The other benefit about the base plate is the integrated Arca Swiss mount, which I'll use when shooting long exposures from a tripod. The grip. Yes, the grip is nice on the E-M1 and certainly better than anything else Olympus has, but I still don't find it as comfortable as the one on my GH4's. I think the biggest "problem" is that it's too narrow when compared to the one on the GH4. Still, it's a minor gripe and not a deal breaker by any stretch of the imagination. The menus. I don't think the menu system is nearly as bad as everyone seemingly makes it out to be. Having said that, it is more convoluted than the Panasonic menu structure, and could make it difficult to find some item that's likely buried on the third page of the "gear K" menu. Overall, I'm very happy with the camera so far (having only played with it for about 2-3 hours last night). I really bought the camera for three reasons: to AF my 50-200, to have IBIS for my primes, and for the long exposure modes like Live Time and Live Composite. There's a local auto-x coming up this weekend that I'll try to attend (temperatures are going to be damn cold though, upper 20's / lower 30's in the morning) where I'll be able to put the 50-200 through its paces with the E-M1 to see just how well it really works. I plan to evaluate the E-M1's performance against my GH4 when it comes to C-AF performance with native lenses like the 35-100 and 45-175, so I'll be sure to include an update about that. Hopefully this thread can shed some light on what I find as good, and what I find slightly annoying (because I haven't come across anything that's "bad") about the E-M1 after having shot Panasonic cameras for the past ~2 years. I'll be sure to update it as I learn more about the camera.