I start this post by asking....do you need a huge sensor with 45+ megapixels to create stunning digital photos? I have recently run into some locals who had to have the newest Nikon D850. BTW... SONY makes the D850 sensor! I reveled in the fact that my kit was the size of a lunchbox, while their kits were the size of a checked luggage bag! They needed a huge tripod, a big heavy lens, it was almost comical on a distant hike. They were struggling... After reviewing their images on Flickr and elsewhere, seeing their photo outcomes, I saw no more detail, dynamic range or stunning colors than from my mirrorless kit. (we were shooting together same scenes) Do you need full frame sensor....not really! There are numerous reviews of D850 vs APSC camera's on You Tube. Although I must say the unrealistic PP of their images was interesting. DSLR' s certainly cannot match the features of mirrorless camera's, although they are trying of late. And with the news that Canon and Nikon are on the path to try and catch up with Sony's Alpha camera's I predict means that eventually pro's will be using them and DSLR's will go the way of film camera's. Nikon is actually working on a new lens mount for a FF mirrorless camera...WOW
Personally I started my serious photographic pursuit many years ago with 35mm film cameras. Having worked in journalism and as a wedding/portrait photographer. Working partime with larger format film cameras as a second photographer for an established studio in Delaware. I also worked at a camera shop in Dover partime working with a film lab and processing while also doing a fulltime job in CATV with a local origination channel. As time went on I shot with Nikon and Olympus film camera's as well as Yashika, Nikormat, Hasselblad and various 4x5, 120 film formats.
So fast forward to the early digital camera's era...I used Kodak DSC-100 when they first arrived on the scene. Later getting a 3mp Canon for a trip to Oahu, (I still like a few of those 3mp images! I got my first APS-C sensored Konica Minolta (now defunked, bought by Sony) camera in the late 90's with a better auto focus lens....It took me a while to learn to not use manual focus as I was so use to this when shooting. As time progressed and I went back as a professional photographer partime and building my business doing some commercial work, web work and a few weddings using Canon and Nikon camera kits. When the Canon 5D's came out I had to have one....one of which I lost on a canoe trip when we capsized on a technical spring river in Florida...(ouch)! Coulda, shouda, wouda! Anyway that's another story.
So I still had a couple Nikon D200 bodies/lenses and a Canon 40d/lenses in the house but were both APS sized sensors. So I used those for numerous commissions for a couple years with great results. Along the way I picked up an Olympus PEN for a fun walk around shooter. WOW I was surprisingly impressed with the results from this fun little camera. I was very interested and perplexed in mirrorless camera's at this time, which was around 2010. While I did not use it for pro work I was liking the results, control, size, build and retro styling. Moving along I purchased a Sony A5000, then to a Sony A6000....I was now hooked on mirrorless...still having several DSLR from Nikon and Canon, they started collecting dust. However I did start using their lenses on the tiny Sony bodies, (which was available with an adapter) another advantage of mirroless designs. Next I jumped to Sony full-frame Alpha's and Fujifilm's XT models, of which I still have.
I started investigating the Olympus OMD's 4/3rds in 2017...i loved the retro styling, the size and weight as I am much older these days. I found the size and weight of larger camera's to be a burden in so many ways. I was hesitant to purchased Olympus OMD's at first due to their high prices for small kits and the 16mp 4/3rds sized sensor seemed technically undesirable. But after renting one for a short trip I was blown away by the results, speed and handling...not to mention the features on board. Having been very pro-active to promote small cameras, point and shoots, and cheap digital cameras for years for internet work. It became obvious that many weren't feeling or even aware that these camera's were capable of stunning captures.
In closing I have been very impressed with the capabilities of the Olympus/Panasonic camera's and lenses, not to mention the superb size, quality, styling and weight of everything...smaller, lighter tripods, bags, lenses, filters, etc. There is a huge selection of glass both high-end and enthusiast grades...while Olympus is still a bit pricey they are competitive with bigger kits.
While I will probably never stick to one camera brand (I love using and playing with numerous brands), I will continue to work with these Olympus and Panasonic models. Will they replace my Sony's....not! But they are really really fun to use!
Have fun and keep it light....be sure to look up some micro 4/3rds images on Flickr and elsewhere!
Here's another perspective and result of the micro four thirds system.