I've had various iPhones and Androids over the years, most recently iPhone 6s+, 7+ and XR. I just yesterday bought a Oneplus 6T and am very happy with it.
I've had the Xr for a few months now and it's been my least favorite iPhone. For me, it's a little heavy compared to even the older pluses. And the display isn't all that much chop for a premium phone. I'm glad it's a work phone, because I don't think I would ever have forked out over $1200 AUD for it.
As much as I appreciate the privacy angle of the Apple ecosystem, it turns out that I've really missed just being able to install what I want on my phone. It's been liberating being able to customize what I want to not what Apple allows you to.
Also, with Oneplus phones, you really do get 'flagship' quality phones without having to fork out the money.
I was a happy owner of the OP2, and currently the OP6. I doubt my next phone will be a OnePlus, though. While the OnePlus are great phones, the prices have risen to flagship levels over the years. The new OP 7 Pro starts at $669, a far cry from the $299 of the original OP One.