It's difficult. The reason for trying the X-T4 is that I really struggle carrying so much gear as daily carry. Not when I'm going out intending to take photos, I could carry the Z9 in my hand all day if I'm out shooting, but to have a camera 'just in case'. The obvious option is a DX Z camera but the DX choice for Z isn't great right now. I thought I'd see if the Fuji could replace my Nikon gear. OK so slightly unfair to compare anything to a Z9 but I only have the Z9 as I didn't get on with the Z7ii AF. I have been told the Fujis aren't action cameras, but I don't shoot action or BIF that much, so overshooting in those situations I could handle so thought I'd try it out.
Anyway, I love love love the colours out of the X-T4. I could shoot in jpeg and never worry about raw processing or file sizes again. The prime lenses are sharp as a razor, small, light weight, and metal construction. Just that worry on the rattling I noticed that makes me question long term reliability. But I've never heard of any problems in this regard as a general issue. I like the form factor, solid construction, lenses with aperture controls again. It's a really enjoyable camera to use other than one point. The AF.
It all really came down to the AF. It was odd, it was fast to acquire focus, but I found it really inconsistent at times and quite slow if something was moving to keep track of the movement. The face tracking got very confused with multiple people in the frame but I didn't try portraits this weekend. I have to say, it was a disappointment for that.
That being said, I'm now trying to justify running both systems, an X-T4 plus a couple of primes for daily carry. Or do go for a Zfc and a couple of Viltrox primes... But those colours... Did I mention the colours are simply beautiful? lol