For me iy's all about how they feel in use and the results I can get with them, I stopped chasing new models years ago when I found that the ones I had did everything I needed. I settled on these Leica M9s in 2017(added the M9-P a while later) and they are my favourite cameras.
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The only problem with the Leicas is no weather sealing so when the weather is bad I have my Fuji X-T2s, I find they are real do-it-alls and can take the wind & rain on Dartmoor.
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For when I want "better" image quality I have Fuji GFX 50S, the first generation, 2017 which tbh out performs my normal requirements but does provide very nice files.
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Unless I outgrow any of these I'm not looking to change them, if they break and I can still get replacements or repairs I will replace/repair rather than "upgrade" but I recognise there will come a time when the models I have are beyond repair and replacement will not be feasible but I'll cross that bridge when I have to.