I have been using the camera for over months and compared it to my OM-D E-M1III or E-M1X. OM-1 represents a significant upgrade in the following areas:PROS:1. Improved new stacked back-illuminated Sony sensor with 1,053 cross-type phase detection points (v.s. 121) and faster TruePic X processor (2-3x faster processing) leading to:a) improved autofocus performance in face and subject detection and tracking; these changes make the hit rate for fast moving subjects (animals, birds, kids, etc.) dramatically better compared to E-M1III or E-M1Xb) improved sensitivity in low light, which is -8Ev on the OM-1 and -6Ev on the E-M1 III (measured with an F1.2 lens)c) maximum of 50fps (with C-AF) and 120fps (AF locked) with electronic shutter and compatible pro lenses (12-40mm F2.8 PRO;12-40mm F2.8 PRO Ⅱ;12-100mm F4.0 IS PRO;40-150mm F2.8 PRO;150-400mm F4.5 TC 1.25x IS PRO;300mm F4.0 IS PRO) (vs. 18 and 60fps)d) number of improvements in movie quality and settings (e.g. 4K up to 60p and 10-bit internal recording without sensor crop, Full HD at 240p with 16% sensor crop; additional HLG (Hybrid Log Gamma) profile; unlimited movie recording time with a single file generated)e) improved speed in computational features like live ND, focus stacking, hand-held high resolution mode (approx 2-2.5x) and additional stop of live ND filter function; now 6 stops effect (ND64) vs 5 stops;f) increased ISO range from 200-6400 to 200-25,600 and in movie mode from 200-6400 to 200-12800; marginally improved noise processing in JPG files, hardly any difference in noise performance and dynamic range of the sensor based on RAW file processingg) improved buffer capacity, but only marginallyh) faster flash sync in electronic shutter mode: OM-1 to sync flash up to 1/100s and ISO 12,800, or 1/50s and ISO 16,000 when using the electronic shutter; by comparison, the E-M1 III can do 1/50s up to ISO 8,000, or 1/20s with higher sensitivities.2. Improved higher resolution viewfinder and LCD screen: Upgrade OLED viewfinder 5.76M vs. 2.36M LCD; the magnification is a bit higher too (0.83x on the OM-1 versus 0.74x on the E-M1 III) and it also features an anti-fog coating. The LCD resolution on OM-1 is 1.62M vs 1.04M3. Improved battery life (approx 20-25%), new battery; can be charged via the USB C port, and also accept power delivery4. Improved more intuitive menu system5. optional bluetooth wireless remote (and battery grip)6. Improved weather sealing (IP53 rating, which is higher than the IPX1 rating found on the E-M1 III)CONS:1. The sensor high ISO performance and dynamic range is virtually unchanged based on RAW file processing; RAW files or movies are still 12 bit only2. The mechanical shutter speed is decreased from 15 fps to 10 fps3. Marginally improved buffer despite higher frame rates4. The old battery and battery grip is not compatible with OM-1; no battery charger is provided5. Fragile micro HDMI (type D) connector6. Higher price (2200$ vs 1600-1700$)Conclusion: OM-1 has a largely improved autofocus precision and speed, better subject tracking with enhanced video features and a higher resolution viewfinder and LCD screen. This is combined with class leading weather-proofing, built-in stabilization, and improved battery life makes it a perfect camera for adventure and wildlife photography. However, if you do not need the improved autofocus, better viewfinder, menus and video features you will be perfectly fine with OM-D E-M1III, OM-D E-M5III or E-M1X with similar image quality for much less price.Update after over 4 months of use (Aug16, 2022) and around 15,000 pictures:PROS:-The hit rate for birds using the 300 mm PRO lens with continuous auto-focus (large area) and subject recognition (birds) is largely improved (by 50-70%) compared to E-M1III and E-M1X.CONS:-Sometimes it loses the focus even with bird detection and numerous images are not in focus using the 300 mm PRO lens-Using the silent shutter and continuous auto-focus (CAF) single point with the 12-100 mm F4 PRO for landscapes/cityscapes sometimes results in out of focus images; this never happened with E-M1III and E-M1X; this also happens using the handheld high resolution mode using CAF. A few days ago a firmware update was released (1.2) to improve the CAF performance, hopefully this will improve/fix these issues-The subject recognition does not work well with numerous animals (e.g. deer).-Update after firmware 1.2 and a few thousand pictures: the above mentioned autofocus issues and subject detection have considerably been improved-Almost every 3-4 weeks 1-3 new dead pixels appears on the sensor, luckily these can be mapped out with the pixel mapping feature; I never observed such phenomenon with previous Olympus cameras-After using several raw processing engines with thousands of pictures I can state with confidence that the noise performance and dynamic rage of the new sensor is virtually identical to the performance of the sensors in E-M1III, E-M1X and E-M5III-The higher resolution viewfinder is great in good light and very useful, however under low light conditions it becomes extremely noisy and falls apart (the old LCD viewfinder was more useful in low light)-The battery grip costs 350$+taxConclusion: I still think that this is an excellent camera for bird photography and fast moving subjects, but not sure that it has any significant advantages for other types of photography (travel, landscape, etc) over the E-M1III, E-M1X and E-M5III.