Looking for a more versatile kit - Fuji x Switch to Sony

Hi,

You're actually talking about TWO changes.  One  is camera choice from a middle resolution Fuji camera to a very high resolution Sony model.  The other is lens choice.  I think you need to establish why you are considering both elements.

My XT4 meets most of my needs.  However, I have looked at the Sony A7R4A for some time.  It has the same sensor pixel pitch as the XT4, but over twice the area.  It appeals to me for detailed landscapes specifically when I want to print large. Thus far, I have resisted the temptation.  I may hire one to try it out.

Think carefully.  There are some downsides....  The A7R4 is heavier than the XT4, same weight as the XH2 - if that matters to you..  And do you need that much resolution?  Every uncompressed raw shot at full res is about 120mb.  That's 8 images per gigb of storage.  To me that makes it a highly specialized camera - not one for general  duties or family travel.  I think I'd actually need to own two systems if I had an A7R4 (or a Fuji GFX, for exactly the same reasons).

On lenses, It's personal.  I can't comment on the Tamron 28-200 - I've never used it.  If you're happy with that style of lens, you might enjoy it.  I have learned that I dislike big zooms.  It's just about preference - I just don't want a camera with a fairly substantial lens attached all the time.  The Tamron is about the same weight as the Fuji 70-300.  (I'd personally rather have a handful of very small, light, sharp primes, but that's me.  These days they're available in Sony - it's  no longer true that all FF lenses are big and heavy.)

Don't know if any of that helps.

Regards, Rod